Abstract: This paper describes the first cloning of the glycerol-3-phosphate dehydrogenase gene (DSGPDH) of Dunaliella salina involving large-scale sequencing of a cDNA library and RACE.Southern blotting was carried out to identify the copy of this gene in this organism. The 3-D structure of this protein was predicted. The protein had a whole functional domain of GPDH and another phosphatase-like domain. This experiment may be helpful for the explanation of the rapid glycerol synthesis in D. salina under hyperosmolarity stress.