SCHEDULE 13G

Amendment No.  0
21VIANET GROUP INC
CLASS A COMMON STOCK
Cusip #90138A103
Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:
[x] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)

Cusip #90138A103
Item 1: Reporting Person - FIL Limited
Item 2: (a)  [ ]
        (b)  [ ]
Item 4: Bermuda
Item 5: 31,888,578
Item 6: 0
Item 7: 32,420,178
Item 8: 0
Item 9: 32,420,178
Item 11: 6.496%
Item 12: FI

Cusip #90138A103
Item 1: Reporting Person - Pandanus Partners, L.P.
Item 2: (a)  [ ]
        (b)  [ ]
Item 4: Delaware
Item 5: 0
Item 6: 0
Item 7: 32,420,178
Item 8: 0
Item 9: 32,420,178
Item 11: 6.496%
Item 12: PN

Cusip #90138A103
Item 1: Reporting Person - Pandanus Associates, Inc.
Item 2: (a)  [ ]
        (b)  [ ]
Item 4: Delaware
Item 5: 0
Item 6: 0
Item 7: 32,420,178
Item 8: 0
Item 9: 32,420,178
Item 11: 6.496%
Item 12: CO



Item 1(a). Name of Issuer:

21VIANET GROUP INC

Item 1(b). Address of Issuer's Principal Executive Offices:

M5, 1 Jiuxianqiao East Rd, Chaoyang District
Beijing,  F4 100016
China

Item 2(a). Name of Person Filing:

FIL Limited

Item 2(b). Address or Principal Business Office or, if None, Residence:

Pembroke Hall, 42 Crow Lane, Hamilton, Bermuda, HM19

Item 2(c). Citizenship:

Not applicable

Item 2(d). Title of Class of Securities:

CLASS A COMMON STOCK

Item 2(e). CUSIP Number:

90138A103

Item 3. This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) or (c)
and the person filing, FIL Limited, is a non-U.S. institution in accordance
with Section 240.13d-1(b)(1)(ii)(J). (Note: See Exhibit A).

If filing as a non-U.S. institution in accordance with Section
240.13d-1(b)(1)(ii)(J), please specify type of institution: Parent holding or
control person.

Item 4. Ownership

(a) Amount Beneficially Owned: 32,420,178

(b) Percent of Class: 6.496%

(c) Number of shares as to which such person has:

(i) sole power to vote or to direct the vote: 31,888,578

(ii) shared power to vote or to direct the vote: 0

(iii) sole power to dispose or to direct the disposition of: 32,420,178

(iv) shared power to dispose or to direct the disposition of: 0


Item 5. Ownership of Five Percent or Less of a Class.

Not applicable.

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

One or more other persons are known to have the right to receive or the power
to direct the receipt of dividends from, or the proceeds from the sale of, the
CLASS A COMMON STOCK of 21VIANET GROUP INC. No one other person's interest in
the CLASS A COMMON STOCK of 21VIANET GROUP INC is more than five percent of
the total outstanding CLASS A COMMON STOCK.

Item 7. Identification and Classification of the Subsidiary Which Acquired the
Security Being Reported on By the Parent Holding Company.

See attached Exhibit A.

Item 8. Identification and Classification of Members of the Group.

Not applicable.

Item 9. Notice of Dissolution of Group.

Not applicable.

Item 10. Certifications.

By signing below I certify that, to the best of my knowledge and belief, the
securities referred to above were acquired and are held in the ordinary course
of business and were not acquired and are not held for the purpose of or with
the effect of changing or influencing the control of the issuer of the
securities and were not acquired and are not held in connection with or as a
participant in any transaction having that purpose or effect. By signing below
I certify that, to the best of my knowledge and belief, the foreign regulatory
scheme applicable to FIL Limited and its various non-U.S. investment
management subsidiaries included on this Schedule 13G is substantially
comparable to the regulatory scheme applicable to the functionally equivalent
U.S. institutions. I also undertake to furnish to the Commission staff, upon
request, information that would otherwise be disclosed in a Schedule 13D.

Signature

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

February 13, 2019
Date

/s/ Kevin M. Meagher
Signature

Kevin M. Meagher
Duly authorized under Power of Attorney effective as of September 20, 2018, by
and on behalf of FIL Limited and its direct and indirect subsidiaries*


* This power of attorney is incorporated herein by reference to Exhibit 24 to
the Schedule 13G filed by FIL Limited on October 9, 2018, accession number:
0000318989-18-000036.


Exhibit A


Pursuant to the instructions in Item 7 of Schedule 13G, the following table
lists the identity and Item 3 classification, if applicable, of each relevant
entity that beneficially owns shares of the security class being reported on
this Schedule 13G.

Entity  ITEM 3 Classification

FIL INVESTMENT MANAGEMENT (HONG KONG) LIMITED * FI


* Entity beneficially owns 5% or greater of the outstanding shares of the
security class being reported on this Schedule 13G.


Pandanus Partners, L.P. ("Pandanus") owns shares of FIL Limited ("FIL") voting
stock. While the percentage of total voting power represented by these shares
of FIL voting stock may fluctuate as a result of changes in the total number
of shares of FIL voting stock outstanding from time to time, it normally
represents more than 25% and less than 48.5% of the total votes which may be
cast by all holders of FIL voting stock. Pandanus Associates, Inc. ("PAI")
acts as general partner of Pandanus. Pandanus is owned by trusts for the
benefit of members of the Johnson family, including FIL's Chairman Abigail P.
Johnson, but disclaims that any such member is a beneficial owner of the
securities reported on this Schedule 13G.

This filing reflects the securities beneficially owned, or that may be deemed
to be beneficially owned, by FIL, certain of its subsidiaries and affiliates,
and other companies (collectively, the "FIL Reporters"). This filing does not
reflect securities, if any, beneficially owned by certain other companies
whose beneficial ownership of securities is disaggregated from that of the FIL
Reporters in accordance with Securities and Exchange Commission Release No.
34-39538 (January 12, 1998).


RULE 13d-1(k)(1) AGREEMENT

The undersigned persons, on February 13, 2019, agree and consent to the joint
filing on their behalf of this Schedule 13G in connection with their
beneficial ownership of the CLASS A COMMON STOCK of 21VIANET GROUP INC at
December 31, 2018.

FIL Limited

By /s/ Kevin M. Meagher
Kevin M. Meagher
Duly authorized under Power of Attorney effective as of September 20, 2018, by
and on behalf of FIL Limited and its direct and indirect subsidiaries*

Pandanus Partners, L.P.

By /s/ Kevin M. Meagher
Kevin M. Meagher
Duly authorized under Power of Attorney effective as of September 25, 2018, by
Pandanus Associates, Inc. on behalf of Pandanus Partners, L.P.*

Pandanus Associates, Inc.

By /s/ Kevin M. Meagher
Kevin M. Meagher
Duly authorized under Power of Attorney effective as of September 25, 2018, by
and on behalf of Pandanus Associates, Inc.*


* This power of attorney is incorporated herein by reference to Exhibit 24 to
the Schedule 13G filed by FIL Limited on October 9, 2018, accession number:
0000318989-18-000036.