**Exhibit 21.1**

 

**LIST OF SUBSIDIARIES**

Duncan Energy Partners L.P. 

as of April 2, 2007

 
|                                       | **Jurisdiction** | ** **                                                                                                                                   |
|--------------------------------------------|------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
| **Name of Subsidiary**                     | **of Formation** | **Effective Ownership******                                                                                                                  |
| Acadian Acquisition, LLC                   | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| Acadian Consulting LLC                     | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| Acadian Gas, LLC                           | Delaware         | Enterprise Products Operating L.P. – 34%

DEP Operating Partnership, L.P. – 66%                                                    |
| Acadian Gas Pipeline System                | Texas            | TXO-Acadian Gas Pipeline, LLC – 50%

MCN-Acadian Gas Pipeline, LLC – 50%                                                           |
| Calcasieu Gas Gathering System             | Texas            | TXO-Acadian Gas Pipeline, LLC – 50%

MCN-Acadian Gas Pipeline, LLC – 50%                                                           |
| Cypress Gas Marketing, LLC                 | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| Cypress Gas Pipeline, LLC                  | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| DEP OLPGP, LLC                             | Delaware         | Duncan Energy Partners L.P. – 100%                                                                                                      |
| DEP Operating Partnership, L.P.            | Delaware         | Duncan Energy Partners L.P. – 99.999%

DEP OLPGP, LLC – 0.001%                                                                     |
| Enterprise Lou-Tex Propylene Pipeline L.P. | Delaware         | Enterprise Products Operating L.P. – 33%

Propylene Pipeline Partnership L.P. – 1%

DEP Operating Partnership, L.P. – 66%     |
| Evangeline Gas Corp.                       | Delaware         | Evangeline Gulf Coast Gas, LLC – 45.05%

Third Parties – 54.95%                                                                    |
| Evangeline Gas Pipeline Company L.P.       | Delaware         | Evangeline Gulf Coast Gas, LLC – 45%

Evangeline Gas Corp. – 10%

Third Party – 45%                                           |
| Evangeline Gulf Coast Gas, LLC             | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| MCN Acadian Gas Pipeline, LLC              | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| MCN Pelican Interstate Gas, LLC            | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| MCN Pelican Transmission LLC               | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
| Mont Belvieu Caverns, LLC                  | Delaware         | Enterprise Products Operating L.P. – 33.365%

Enterprise Products OLPGP, Inc. – 0.635%

DEP Operating Partnership, L.P. – 66% |
| Neches Pipeline System                     | Texas            | TXO-Acadian Gas Pipeline, LLC – 50%

MCN-Acadian Gas Pipeline, LLC – 50%                                                           |
| Pontchartrain Natural Gas System           | Texas            | TXO-Acadian Gas Pipeline, LLC – 50%

MCN-Acadian Gas Pipeline, LLC – 50%                                                           |
| Sabine Propylene Pipeline L.P.             | Texas            | Enterprise Products Operating L.P. – 33%

Propylene Pipeline Partnership L.P. – 1%

DEP Operating Partnership, L.P. – 66%     |
| South Texas NGL Pipeline LLC               | Delaware         | Enterprise Products Operating L.P. – 34%

DEP Operating Partnership, L.P. – 66%                                                    |
| TXO-Acadian Gas Pipeline, LLC              | Delaware         | Acadian Gas, LLC – 100%                                                                                                                 |
|                                       |             |                                                                                                                                         |