Geothermal history is one of the important contens in hydrocarbon research. Onthe basis of over one thousand vitrinite reflectance data from more than 50 boreholes,this paper studied summarily the Cenozoic geothermal history and its features ofthe west sector shelf of the northern South China Sea.In each historical stage of Cenozoic, the geotemperature of Yingqiong Basin,Zhushan Basin and Beibuwan Basin declined successively. This geotemperature distribution tendency is similar to the present one. Since Cenozoic era, the geotemperatures of three major basins all tended to decline progressively in the past and riseagain at present. The geotemperature fluctuates within a narrow range in ZhushanBasin. In Yingqiong Basin, the geothemperature of Eogene was even higher than present. In Beibuwan Basin, the features of relatively low temperature in Neogene areobvious.This geotemperature descrepancy in different regions and the change with timeare not primarily due to the difference or variety in deep geothermal background,but are the result in diversified sediment’s thermophysical properties in the regionsof palaeogeotemperature survey. Nevertheless, these disscrepancy and change in geotemperature are real as well, actually they are significant in illustrating the generation of hydrocarbons and their evolution.