<SEC-DOCUMENT>0001752724-20-059708-index.html : 20200325
<SEC-HEADER>0001752724-20-059708.hdr.sgml : 20200325
<ACCEPTANCE-DATETIME>20200325170003
ACCESSION NUMBER:		0001752724-20-059708
CONFORMED SUBMISSION TYPE:	NPORT-P
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20200131
FILED AS OF DATE:		20200325
PERIOD START:           	20201031

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MFS SERIES TRUST X
		CENTRAL INDEX KEY:			0000783740
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1130

	FILING VALUES:
		FORM TYPE:		NPORT-P
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-04492
		FILM NUMBER:		20742909

	BUSINESS ADDRESS:	
		STREET 1:		111 HUNTINGTON AVENUE
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199
		BUSINESS PHONE:		18006372929

	MAIL ADDRESS:	
		STREET 1:		111 HUNTINGTON AVENUE
		STREET 2:		24TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MFS GOVERNMENT MORTGAGE FUND
		DATE OF NAME CHANGE:	19930408

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MFS GOVERNMENT INCOME PLUS FUND
		DATE OF NAME CHANGE:	19930312

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MASSACHUSETTS MFS GOVERNMENT INCOME PLUS FUND
		DATE OF NAME CHANGE:	19921015
<SERIES-AND-CLASSES-CONTRACTS-DATA>
<EXISTING-SERIES-AND-CLASSES-CONTRACTS>
<SERIES>
<OWNER-CIK>0000783740
<SERIES-ID>S000033795
<SERIES-NAME>MFS Emerging Markets Debt Local Currency Fund
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104416
<CLASS-CONTRACT-NAME>A
<CLASS-CONTRACT-TICKER-SYMBOL>EMLAX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104417
<CLASS-CONTRACT-NAME>B
<CLASS-CONTRACT-TICKER-SYMBOL>EMLBX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104418
<CLASS-CONTRACT-NAME>C
<CLASS-CONTRACT-TICKER-SYMBOL>EMLCX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104419
<CLASS-CONTRACT-NAME>I
<CLASS-CONTRACT-TICKER-SYMBOL>EMLIX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104420
<CLASS-CONTRACT-NAME>R1
<CLASS-CONTRACT-TICKER-SYMBOL>EMLJX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104421
<CLASS-CONTRACT-NAME>R2
<CLASS-CONTRACT-TICKER-SYMBOL>EMLKX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104422
<CLASS-CONTRACT-NAME>R3
<CLASS-CONTRACT-TICKER-SYMBOL>EMLLX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000104423
<CLASS-CONTRACT-NAME>R4
<CLASS-CONTRACT-TICKER-SYMBOL>EMLMX
</CLASS-CONTRACT>
<CLASS-CONTRACT>
<CLASS-CONTRACT-ID>C000123138
<CLASS-CONTRACT-NAME>R6
<CLASS-CONTRACT-TICKER-SYMBOL>EMLNX
</CLASS-CONTRACT>
</SERIES>
</EXISTING-SERIES-AND-CLASSES-CONTRACTS>
</SERIES-AND-CLASSES-CONTRACTS-DATA>
</SEC-HEADER>
<DOCUMENT>
<TYPE>NPORT-P
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
Document 1 - file: primary_doc.html

Document 1 - RAW XML: primary_doc.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>NPORT-EX
<SEQUENCE>2
<FILENAME>NPORT_754276796349887.htm
<TEXT>
Document 2 - file: NPORT_754276796349887.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>img273793bd2.gif
<TEXT>
Document 3 - file: img273793bd2.gif

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>imgc8e2049d1.gif
<TEXT>
Document 4 - file: imgc8e2049d1.gif

</DOCUMENT>
</SEC-DOCUMENT>