Abstract: The Taixi'nan Basin is one of the potential areas containing gas hydrate and located on the continental slope of South China Sea. The study of the hydrate stability zone (HSZ) is of great significance to the research of the deposition and distribution features of marine gas hydrate, and its resource assessment. Based on the gas hydrate data from SO-177 Sino-Germany cooperation cruise, we calculated the thickness of the gas hydrate stability zone in the areas of A and B in the Taixi'nan Basin. Furthermore, with the Geographic Information System (GIS) as a tool, we calculated the amount of methane contained in gas hydrate under normal condition.It is:8.573 9×10¹¹~5.144 3×10¹² m³ for area A, 1.451 8×10¹²~8.711 1×10¹² m³ for area B, and 2.302 9×10¹²~13.854 4×10¹² m³ in total. The results show that there is great methane resource potential in the Taixi'nan basin.