Exhibit 21.1

                SUBSIDIARIES OF REGISTRANT AT DECEMBER 31, 2005


The companies listed below are directly or indirectly owned 100% by GSE Systems,
Inc. and are included in its consolidated financial statements.

*    GSE Engineering Systems (Beijing) Company Ltd., GSE Erudite Software, Inc.,
     GSE Power Systems AB, GSE Process  Solutions,  Inc.,  GSE Services  Company
     L.L.C. and MSHI, Inc., are wholly owned subsidiaries of GSE Systems, Inc.

*    GSE  Government  & Military  Simulation  Systems,  Inc.  is a wholly  owned
     subsidiary of GSE Power Systems, Inc. which is a wholly owned subsidiary of
     MSHI, Inc.

*    GSE  Process  Solutions  BV is a wholly  owned  Subsidiary  of GSE  Process
     Solutions, Inc.


Name                                      Place of Incorporation or Organization
- ------                                  ----------------------------------------
GSE Engineering Systems (Beijing) Company, Ltd         Peoples Republic of China
GSE Erudite Software, Inc.                             State of Delaware
GSE Power Systems AB                                   Sweden
GSE Process Solutions, Inc.                            State of Delaware
GSE Services Company L.L.C.                            State of Delaware
MSHI, Inc.                                             State of Virginia
GSE Government & Military Simulation Systems, Inc.     State of Delaware
GSE Power Systems, Inc.                                State of Delaware
GSE Process Solutions, BV                              Netherlands