**Exhibit21.1**

 
| **Subsidiary**                                        | ** ** | **Jurisdiction  of   Organization** |
|-------------------------------------------------------|------------|-------------------------------------|
| U-Store-It, L.P.                                      |       | Delaware                            |
| Acquiport/Amsdell III,  LLC                           |       | Delaware                            |
| Acquiport/Amsdell IV,  LLC                            |       | Delaware                            |
| Acquiport/Amsdell VI,  LLC                            |       | Delaware                            |
| Lantana Property  Owner’s Association, Inc. |       | Florida                             |
| U-Store-It Development  LLC                           |       | Delaware                            |
| U-Store-It Mini  Warehouse Co.                        |       | Ohio                                |
| U-Store-It Trust  Luxembourg S.ar.l.                  |       | Luxembourg                          |
| USI II, LLC                                           |       | Delaware                            |
| USI Overseas  Development Holding L.P.                |       | Delaware                            |
| USI Overseas  Development LLC                         |       | Delaware                            |
| USIFB LP                                              |       | London                              |
| USIFB LLP                                             |       | London                              |
| YASKY LLC                                             |       | Delaware                            |
| YSI I LLC                                             |       | Delaware                            |
| YSI II LLC                                            |       | Delaware                            |
| YSI III LLC                                           |       | Delaware                            |
| YSI IV LLC                                            |       | Delaware                            |
| YSI IX GP LLC                                         |       | Delaware                            |
| YSI IX LP                                             |       | Delaware                            |
| YSI IX LP LLC                                         |       | Delaware                            |
| YSI Management LLC                                    |       | Delaware                            |
| YSI RT LLC                                            |       | Delaware                            |
| YSI V LLC                                             |       | Delaware                            |
| YSI VI LLC                                            |       | Delaware                            |
| YSI VII GP LLC                                        |       | Delaware                            |
| YSI VII LP                                            |       | Delaware                            |
| YSI VII LP LLC                                        |       | Delaware                            |
| YSI VIII GP LLC                                       |       | Delaware                            |
| YSI VIII LP                                           |       | Delaware                            |
| YSI VIII LP LLC                                       |       | Delaware                            |
| YSI X GP LLC                                          |       | Delaware                            |
| YSI X LP                                              |       | Delaware                            |
| YSI X LP LLC                                          |       | Delaware                            |
| YSI XI GP LLC                                         |       | Delaware                            |
| YSI XI LP                                             |       | Delaware                            |
| YSI XI LP LLC                                         |       | Delaware                            |
| YSI XII GP LLC                                        |       | Delaware                            |
| YSI XII LP                                            |       | Delaware                            |
| YSI XII LP LLC                                        |       | Delaware                            |
| YSI XIII GP LLC                                       |       | Delaware                            |
| YSI XIII LP                                           |       | Delaware                            |
| YSI XIII LP LLC                                       |       | Delaware                            |
| YSI XIV GP LLC                                        |       | Delaware                            |
| YSI XIV LP                                            |       | Delaware                            |
| YSI XIV LP LLC                                        |       | Delaware                            |
| YSI XV LLC                                            |       | Delaware                            |
| YSI XVI LLC                                           |       | Delaware                            |
| YSI XVII GP LLC                                       |       | Delaware                            |

 

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| YSI XVII LP                   |   | Delaware |
|-------------------------------|--------|----------|
| YSI XVII LP LLC               |   | Delaware |
| YSI XX GP LLC                 |   | Delaware |
| YSI XX LP                     |   | Delaware |
| YSI XX LP LLC                 |   | Delaware |
| YSI XXI LLC                   |   | Delaware |
| YSI XXIII LLC                 |   | Delaware |
| YSI XXIV GP LLC               |   | Delaware |
| YSI XXIV LP                   |   | Delaware |
| YSI XXIV LP LLC               |   | Delaware |
| YSI XXIX GP LLC               |   | Delaware |
| YSI XXIX LP                   |   | Delaware |
| YSI XXIX LP LLC               |   | Delaware |
| YSI XXV GP LLC                |   | Delaware |
| YSI XXV LP                    |   | Delaware |
| YSI XXV LP LLC                |   | Delaware |
| YSI XXVI GP LLC               |   | Delaware |
| YSI XXVI LP                   |   | Delaware |
| YSI XXVI LP LLC               |   | Delaware |
| YSI XXVII GP LLC              |   | Delaware |
| YSI XXVII LP                  |   | Delaware |
| YSI XXVII LP LLC              |   | Delaware |
| YSI XXVIII GP LLC             |   | Delaware |
| YSI XXVIII LP                 |   | Delaware |
| YSI XXVIII LP LLC             |   | Delaware |
| YSI XXX LLC                   |   | Delaware |
| YSI XXXI LLC                  |   | Delaware |
| YSI XXXII LLC                 |   | Delaware |
| YSI XXXIII LLC                |   | Delaware |
| YSI XXXIIIA LLC               |   | Delaware |
| YSI XXXIV LLC                 |   | Delaware |
| YSI XXXV LLC                  |   | Delaware |
| YSI XXXVII LLC                |   | Delaware |
| YSI XXXVIII LLC               |   | Delaware |
| YSI XXXIX LLC                 |   | Delaware |
| YSI XXXX LLC                  |   | Delaware |
| YSI XXXXI LLC                 |   | Delaware |
| YSI XXXXII LLC                |   | Delaware |
| YSI XXXXIII LLC               |   | Delaware |
| YSI XXXXIV LLC                |   | Delaware |
| YSI XXXXV LLC                 |   | Delaware |
| YSI XXXXVI LLC                |   | Delaware |
| YSI XXXXVII LLC               |   | Delaware |
| YSI XXXXVIII LLC              |   | Delaware |
| YSI XLIX LLC                  |   | Delaware |
| YSI L LLC                     |   | Delaware |
| YSI Venture LP LLC            |   | Delaware |
| YSI Venture GP LLC            |   | Delaware |
| YSI-HART Limited  Partnership |   | Delaware |
| YSI HART TRS, Inc.       |   | Delaware |

 

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