<SEC-DOCUMENT>0001752724-25-185830-index.html : 20250811
<SEC-HEADER>0001752724-25-185830.hdr.sgml : 20250811
<ACCEPTANCE-DATETIME>20250811134500
ACCESSION NUMBER:		0001752724-25-185830
CONFORMED SUBMISSION TYPE:	N-CEN
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20250531
FILED AS OF DATE:		20250811
DATE AS OF CHANGE:		20250811
EFFECTIVENESS DATE:		20250811

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKROCK SERIES, INC.
		CENTRAL INDEX KEY:			0001062806
		ORGANIZATION NAME:           	
		EIN:				000000000
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		N-CEN
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-08797
		FILM NUMBER:		251201324

	BUSINESS ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			09809
		BUSINESS PHONE:		800-441-7762

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			09809

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MERCURY FUNDS INC
		DATE OF NAME CHANGE:	20010827

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MERCURY ASSET MANAGEMENT FUNDS INC
		DATE OF NAME CHANGE:	19980714

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MERCURY ALPHA FUND INC
		DATE OF NAME CHANGE:	19980601
<SERIES-AND-CLASSES-CONTRACTS-DATA>
<EXISTING-SERIES-AND-CLASSES-CONTRACTS>
<SERIES>
<OWNER-CIK>0001062806
<SERIES-ID>S000002291
<SERIES-NAME>BlackRock International Fund
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000005981
<CLASS-CONTRACT-NAME>Investor A
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000005983
<CLASS-CONTRACT-NAME>Investor C
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000005984
<CLASS-CONTRACT-NAME>Institutional
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000101856
<CLASS-CONTRACT-NAME>Class R Shares
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000198221
<CLASS-CONTRACT-NAME>Class K
</CLASS-CONTRACT>
</SERIES>
</EXISTING-SERIES-AND-CLASSES-CONTRACTS>
</SERIES-AND-CLASSES-CONTRACTS-DATA>
</SEC-HEADER>
<DOCUMENT>
<TYPE>N-CEN
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
Document 1 - file: primary_doc.html

Document 1 - RAW XML: primary_doc.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>INTERNAL CONTROL RPT
<SEQUENCE>2
<FILENAME>brseriesinc.htm
<TEXT>
Document 2 - file: brseriesinc.htm

</DOCUMENT>
</SEC-DOCUMENT>