| Subsidiaries of Franklin Street Properties Corp. | Exhibit 21.1 |
|--------------------------------------------------|--------------|

| Name                                                 | Jurisdiction of Organization |
|------------------------------------------------------|------------------------------|
| FSP 3150 Fairview Park Drive LLC                     | Delaware                     |
| FSP 380 Interlocken Corp.                            | Delaware                     |
| FSP 390 Interlocken LLC                              | Delaware                     |
| FSP 4807 Stonecroft Boulevard LLC                    | Delaware                     |
| FSP Addison Circle Corp.                             | Delaware                     |
| FSP Addison Circle Limited Partnership               | Texas                        |
| FSP Addison Circle LLC                               | Delaware                     |
| FSP Blue Lagoon Drive Corp.                          | Delaware                     |
| FSP Blue Lagoon Drive LLC                            | Delaware                     |
| FSP Bollman Place Limited Partnership                | Massachusetts                |
| FSP Collins Crossing Corp.                           | Delaware                     |
| FSP Collins Crossing Limited Partnership             | Texas                        |
| FSP Collins Crossing LLC                             | Delaware                     |
| FSP Congress Center LLC                              | Delaware                     |
| FSP Dulles Virginia LLC                              | Delaware                     |
| FSP East Baltimore Street LLC                        | Delaware                     |
| FSP Eden Bluff Corporate Center I LLC                | Delaware                     |
| FSP Eldridge Green Corp.                             | Delaware                     |
| FSP Eldridge Green Limited Partnership               | Texas                        |
| FSP Eldridge Green LLC                               | Delaware                     |
| FSP Forest Park IV LLC                               | Delaware                     |
| FSP Forest Park IV NC Limited Partnership            | North Carolina               |
| FSP Greenwood Plaza Corp.                            | Delaware                     |
| FSP Hillview Center Limited Partnership              | Massachusetts                |
| FSP Holdings LLC                                     | Delaware                     |
| FSP Innsbrook Corp.                                  | Delaware                     |
| FSP Investments LLC                                  | Massachusetts                |
| FSP Lakeside Crossing I LLC                          | Delaware                     |
| FSP Liberty Plaza Limited Partnership                | Texas                        |
| FSP Montague Business Center Corp.                   | Delaware                     |
| FSP Northwest Point LLC                              | Delaware                     |
| FSP One Overton Park LLC                             | Delaware                     |
| FSP Park Seneca Limited Partnership                  | Massachusetts                |
| FSP Park Ten Development Corp.                       | Delaware                     |
| FSP Park Ten Development LLC                         | Delaware                     |
| FSP Park Ten Limited Partnership                     | Texas                        |
| FSP Park Ten LLC                                     | Delaware                     |
| FSP Park Ten Phase II  Limited Partnership | Texas                        |

----

| Subsidiaries of Franklin Street Properties Corp. | Exhibit 21.1 |
|--------------------------------------------------|--------------|

| Name                                              | Jurisdiction of Organization |
|---------------------------------------------------|------------------------------|
| FSP Property Management LLC                       | Massachusetts                |
| FSP Protective TRS Corp.                          | Massachusetts                |
| FSP REIT Protective Trust                         | Massachusetts                |
| FSP River Crossing LLC                            | Delaware                     |
| FSP Southfield Centre Limited Partnership         | Massachusetts                |
| FSP Willow Bend Office Center Corp.               | Delaware                     |
| FSP Willow Bend Office Center Limited Partnership | Texas                        |
| FSP Willow Bend Office Center LLC                 | Delaware                     |
|                                              |                         |
|                                              |                         |