UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM N-Q

                   QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS
    OF REGISTERED MANAGEMENT INVESTMENT COMPANY



  Investment Company Act file number 811-01466


                               Pioneer Fund
               (Exact name of registrant as specified in charter)


                       60 State Street, Boston, MA 02109
              (Address of principal executive offices) (ZIP code)


            Terrence J. Cullen, Pioneer Investment Management, Inc.,
                       60 State Street, Boston, MA 02109
                    (Name and address of agent for service)


Registrant's telephone number, including area code:  (617) 742-7825


Date of fiscal year end:  December 31

Date of reporting period:  March 31, 2017

Form N-Q is to be used by management investment companies, other than small
business investment companies registered on Form N-5 (239.24 and 274.5 of this
chapter), to file reports with the Commission, not later than 60 days after
close of the first and third fiscal quarters, pursuant to Rule 30b1-5 under
the Investment Company Act of 1940 (17 CFR 270.30b1-5).  The Commission may
use the information provided on Form N-Q in its regulatory, disclosure review,
inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q,
and the Commission will make this information public. A registrant is not
required to respond to the collection of information contained in Form N-Q
unless the Form displays a currently valid Office of Management and Budget
("OMB") control number. Please direct comments concerning the accuracy of the
information collection burden estimate and any suggestions for reducing the
burden to Secretary, Securities and Exchange Commission, 450 Fifth Street, NW,
Washington, DC 20549-0609.  The OMB has reviewed this collection of information
under the clearance requirements of 44 U.S.C. ss. 3507.


<PAGE>
ITEM 1. Schedule of Investments.

File the schedules as of the close of the reporting period as set forth in
ss. 210.12-12  12-14 of Regulation S-X [17 CFR 210.12-12  12-14]. The
schedules need not be audited.

		Pioneer Fund
		Schedule of Investments 3/31/17 (unaudited)
	Shares			Value
		COMMON STOCKS - 99.4%
		Energy - 6.3%
		Oil & Gas Equipment & Services - 3.6%
	2,240,000	Schlumberger, Ltd.	$	174,944,000
		Oil & Gas Exploration & Production - 2.7%
	1,361,000	EOG Resources, Inc.	$	132,765,550
		Total Energy	$	307,709,550
		Materials - 2.0%
		Diversified Chemicals - 1.3%
	1,045,000	The Dow Chemical Co.	$	66,399,300
		Specialty Chemicals - 0.7%
	260,000	Ecolab, Inc.	$	32,588,400
		Total Materials	$	98,987,700
		Capital Goods - 2.9%
		Aerospace & Defense - 0.9%
	275,200	Raytheon Co.	$	41,968,000
		Industrial Conglomerates - 2.0%
	784,000	Honeywell International, Inc.	$	97,898,080
		Total Capital Goods	$	139,866,080
		Commercial Services & Supplies - 1.3%
		Environmental & Facilities Services - 1.3%
	852,000	Waste Management, Inc.	$	62,127,840
		Total Commercial Services & Supplies	$	62,127,840
		Transportation - 5.6%
		Air Freight & Logistics - 2.2%
	546,500	FedEx Corp.	$	106,649,475
		Railroads - 3.4%
	1,445,000	Kansas City Southern	$	123,923,200
	375,000	Union Pacific Corp.		39,720,000
			$	163,643,200
		Total Transportation	$	270,292,675
		Automobiles & Components - 1.1%
		Auto Parts & Equipment - 1.1%
	1,225,000	BorgWarner, Inc.	$	51,192,750
		Total Automobiles & Components	$	51,192,750
		Consumer Services - 0.9%
		Restaurants - 0.9%
	765,500	Starbucks Corp.	$	44,697,545
		Total Consumer Services	$	44,697,545
		Media - 3.7%
		Broadcasting - 1.8%
	1,116,000	Scripps Networks Interactive, Inc.	$	87,460,920
		Cable & Satellite - 1.1%
	838,800	DISH Network Corp.	$	53,255,412
		Movies & Entertainment - 0.8%
	364,000	The Walt Disney Co.	$	41,273,960
		Total Media	$	181,990,292
		Retailing - 4.5%
		Apparel Retail - 1.2%
	736,500	The TJX Companies, Inc.	$	58,242,420
		Home Improvement Retail - 2.4%
	813,813	The Home Depot, Inc.	$	119,492,163
		Specialty Stores - 0.9%
	455,000	Tiffany & Co.	$	43,361,500
		Total Retailing	$	221,096,083
		Food & Staples Retailing - 2.1%
		Drug Retail - 2.1%
	1,293,000	CVS Health Corp.	$	101,500,500
		Total Food & Staples Retailing	$	101,500,500
		Food, Beverage & Tobacco - 5.9%
		Soft Drinks - 2.9%
	1,273,300	PepsiCo., Inc.	$	142,431,338
		Packaged Foods & Meats - 3.0%
	759,000	Campbell Soup Co.	$	43,445,160
	921,389	The Hershey Co.		100,661,748
			$	144,106,908
		Total Food, Beverage & Tobacco	$	286,538,246
		Household & Personal Products - 1.2%
		Household Products - 1.2%
	416,000	The Clorox Co.	$	56,089,280
		Total Household & Personal Products	$	56,089,280
		Health Care Equipment & Services - 6.2%
		Health Care Equipment - 2.6%
	1,541,094	Medtronic Plc	$	124,150,533
		Health Care Supplies - 0.8%
	650,000	Dentsply Sirona, Inc.	$	40,586,000
		Managed Health Care - 2.8%
	823,000	UnitedHealth Group, Inc.	$	134,980,230
		Total Health Care Equipment & Services	$	299,716,763
		Pharmaceuticals, Biotechnology & Life Sciences - 7.6%
		Biotechnology - 3.1%
	885,000	Celgene Corp. *	$	110,120,550
	313,000	Incyte Corp. *		41,838,710
			$	151,959,260
		Pharmaceuticals - 4.5%
	809,000	Eli Lilly & Co.	$	68,044,990
	3,108,500	Pfizer, Inc.		106,341,785
	792,800	Zoetis, Inc.		42,311,736
			$	216,698,511
		Total Pharmaceuticals, Biotechnology & Life Sciences	$	368,657,771
		Banks - 9.1%
		Diversified Banks - 7.6%
	2,745,000	JPMorgan Chase & Co.	$	241,120,800
	2,520,500	US Bancorp		129,805,750
			$	370,926,550
		Regional Banks - 1.5%
	586,700	The PNC Financial Services Group, Inc.	$	70,544,808
		Total Banks	$	441,471,358
		Diversified Financials - 4.1%
		Asset Management & Custody Banks - 1.8%
	228,400	BlackRock, Inc.	$	87,593,684
		Investment Banking & Brokerage - 2.3%
	481,300	The Goldman Sachs Group, Inc.	$	110,564,236
		Total Diversified Financials	$	198,157,920
		Insurance - 3.2%
		Multi-line Insurance - 0.9%
	854,000	The Hartford Financial Services Group, Inc.	$	41,051,780
		Property & Casualty Insurance - 2.3%
	834,900	Chubb, Ltd.	$	113,755,125
		Total Insurance	$	154,806,905
		Software & Services - 14.3%
		Internet Software & Services - 7.4%
	290,400	Alphabet, Inc. (Class A)	$	246,201,120
	1,045,000	eBay, Inc. *		35,080,650
	572,000	Facebook, Inc. *		81,252,600
			$	362,534,370
		Data Processing & Outsourced Services - 1.5%
	812,300	Visa, Inc.	$	72,189,101
		Systems Software - 5.4%
	209,500	Check Point Software Technologies, Ltd. *	$	21,507,270
	2,695,319	Microsoft Corp.		177,513,709
	1,400,000	Oracle Corp.		62,454,000
			$	261,474,979
		Total Software & Services	$	696,198,450
		Technology Hardware & Equipment - 6.0%
		Communications Equipment - 2.2%
	3,178,000	Cisco Systems, Inc.	$	107,416,400
		Computer Storage & Peripherals - 3.8%
	1,293,000	Apple, Inc.	$	185,752,380
		Total Technology Hardware & Equipment	$	293,168,780
		Semiconductors & Semiconductor Equipment - 5.1%
		Semiconductor Equipment - 1.2%
	472,000	Lam Research Corp.	$	60,585,920
		Semiconductors - 3.9%
	1,268,000	Analog Devices, Inc.	$	103,912,600
	2,331,500	Intel Corp.		84,097,205
			$	188,009,805
		Total Semiconductors & Semiconductor Equipment	$	248,595,725
		Telecommunication Services - 3.3%
		Integrated Telecommunication Services - 3.3%
	3,840,000	AT&T, Inc.	$	159,552,000
		Total Telecommunication Services	$	159,552,000
		Utilities - 3.0%
		Electric Utilities - 3.0%
	2,153,700	American Electric Power Co., Inc.	$	144,577,881
		Total Utilities	$	144,577,881
		TOTAL COMMON STOCKS
		(Cost $3,636,297,590)	$	4,826,992,094
	Principal Amount ($)
		TEMPORARY CASH INVESTMENT - 0.2%
		Repurchase Agreement - 0.2%
	12,195,000	$12,195,000 ScotiaBank, 0.81%, dated 3/31/17 plus accrued interest on 4/3/17
		collateralized by the following:
		$8,275,750 Federal National Mortgage Association (ARM), 2.272%-3.487%, 5/1/38-10/1/46
		$4,163,990 Federal National Mortgage Association, 3.5-5.5%, 1/1/26-1/1/47	$	12,195,000
		TOTAL TEMPORARY CASH INVESTMENT
		(Cost $12,195,000)	$	12,195,000
		TOTAL INVESTMENT IN SECURITIES - 99.6%
		(Cost $3,648,492,590) (a)	$	4,839,187,094
		OTHER ASSETS & LIABILITIES - 0.4%	$	17,637,788
		TOTAL NET ASSETS - 100.0%	$	4,856,824,882
	*	Non-income producing security.
	(a)	At March 31, 2017, the net unrealized appreciation on investments based on
		cost for federal income tax purposes of $3,648,492,590 was as follows:
		Aggregate gross unrealized appreciation for all investments in which
		there is an excess of value over tax cost	$	1,198,103,803
		Aggregate gross unrealized depreciation for all investments in which
		there is an excess of tax cost over value		(7,409,299)
		Net unrealized appreciation	$	1,190,694,504
Various inputs are used in determining the value of the Fund's investments.  These inputs are summarized in the three broad levels listed below.
Level 1 – quoted prices in active markets for identical securities.
Level 2 – other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.)  See Notes to Financial Statements — Note 1A.
Level 3 – significant unobservable inputs (including the Fund's own assumptions in determining fair value of investments)  See Notes to Financial Statements — Note 1A.
The following is a summary of the inputs used as of March 31, 2017, in valuing the Fund's investments:

	Level 1		Level 2		Level 3		Total
Common Stocks	$	4,826,992,094	$	-	$	-	$	4,826,992,094
Repurchase Agreement		-		12,195,000		-		12,195,000
Total	$	4,826,992,094	$	-	$	-	$	4,826,992,094
During the period ended March 31, 2017, there were no transfers between Levels 1, 2 and 3.

ITEM 2. CONTROLS AND PROCEDURES. (a) Disclose the conclusions of the registrant's principal executive and principal financial officers, or persons performing similar functions, regarding the effectiveness of the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Act (17 CFR 270.30a-3(c))) as of a date within 90 days of the filing date of the report that includes the disclosure required by this paragraph, based on the evaluation of these controls and procedures required by Rule 30a-3(b) under the Act (17 CFR 270.30a-3(b))) and Rule 13a-15(b) or 15d-15(b) under the Exchange Act (17 CFR 240.13a-15(b) or 240.15d-15(b)). The registrant's principal executive officer and principal financial officer have concluded that the registrant's disclosure controls and procedures are effective based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this report. (b) Disclose any change in the registrant's internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting. There were no significant changes in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting. ITEM 3. EXHIBITS. File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2(a)), exactly as set forth below: CERTIFICATIONS I, [identify the certifying individual], certify that: 1. I have reviewed this report on Form N-Q of [identify registrant]; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; 3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed; 4. The registrants other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared; (b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles; (c) Evaluated the effectiveness of the registrants disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and (d) Disclosed in this report any change in the registrants internal control over financial reporting that occurred during the registrants most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrants internal control over financial reporting; and 5. The registrants other certifying officer(s) and I have disclosed to the registrants auditors and the audit committee of the registrants board of directors (or persons performing the equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrants ability to record, process, summarize, and report financial information; and (b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrants internal control over financial reporting. Date: [Signature] [Title] Filed herewith. <PAGE> SIGNATURES [See General Instruction F] Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. (Registrant) Pioneer Fund By (Signature and Title)* /s/ Lisa M.Jones ----------------------- Lisa M.Jones, President and Chief Executive Officer Date May 26, 2017 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. By (Signature and Title)* /s/ Lisa M.Jones ----------------------- Lisa M.Jones, President and Chief Executive Officer Date May 26, 2017 By (Signature and Title)* /s/ Mark E. Bradley ----------------- Mark E. Bradley, Treasurer and Chief Accounting and Financial Officer Date May 26, 2017 * Print the name and title of each signing officer under his or her signature.