The Cenozoic sedimentary basins around Xisha Islands distribute in the deep water region in the northwest part of South China Sea. Three tectonic movements and two tectonic evolutions, one rift-faulting and one depression, have been undergone in this region since Cenozoic era. As a result, a large thickness of Cenozoic sediments deposited in the North Depression Belt and Zhongjian Depression. Source rock and reservoirs mainly formed respectively during the early and the late rift-faulting stages while reservoirs and regional cover formed respectively during the early and the late depression stages. It is deemed that there are excellent source-reservoir-caprock conditions where. In South Depression Belt, affected by intensive tectonic movements and accompanying high geothermal gradient, the ocean crust basement occurred in local and so depressions developed late. It is deduced that the hydrocarbon accumulation model of these peripheral basins is probably similar with that of Yingehai Basin, in which the marine middle Miocene mudstone is of good hydrocarbon-generating potential and the deep-water channel sandstone can be severed as reservoirs with marine mudstone acted as the regional cover. By analysis of the characteristics of hydrocarbon plays in every basins or depression, it is concluded that abundant hydrocarbon resource exists in the Xisha Islands region which is significant for exploration.