Report of Foreign Issuer (6-k)

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SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer
Pursuant to Rule 13a-16 or 15d-16 of
the Securities Exchange Act of 1934

January 2018

Commission File Number: 001-37925

GDS Holdings Limited
(Registrant's name)

2/F, Tower 2, Youyou Century Place
428 South Yanggao Road
Pudong, Shanghai 200127
People's Republic of China
(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F ý Form 40-F o

Indicate by check mark if the registrant is submitting the Form 6-K on paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K on paper as permitted by Regulation S-T Rule 101(b)(7): o

EXHIBITS

Exhibit 99.1 — Unaudited Condensed Consolidated Financial Statements

EX-101.INS XBRL Taxonomy Instance Document
EX-101.SCH XBRL Taxonomy Extension Schema Document
EX-101.CAL XBRL Taxonomy Calculation Linkbase Document
EX-101.DEF XBRL Taxonomy Extension Definition Linkbase Document
EX-101.LAB XBRL Taxonomy Label Linkbase Document
EX-101.PRE XBRL Taxonomy Presentation Linkbase Document

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.