Abstract: Gas hydrates as a new type of clean energy resources are expected to have the great potential to replace coal, oil and natural gas in the 21st century. The South China Sea abounds in gas hydrate resources. Up to now, abundant gas hydrate resources have been explored in the Shenhu, Dongsha and Haima areas on the northern slope of the South China Sea. The present paper deals with geological conditions for the occurrence of the gas hydrates, recognition of bottom simulating reflection (BSR)from the geophysical profiles and calculation of the thickness of gas hydrate stability zones in the southern uplift zone of the Qiongdongnan Basin. The findings show that the southern uplift zone of the Qiongdongnan Basin is conspicuous by developed fluid leakage structures, plentiful free gas, discontinuous and strong amplitudes of bottom simulating reflection, and tremendous thickness of the gas hydrate stability zones, and thus will be highly prospective for the exploration of the gas hydrate resources in the study area.