Abstract: Subdivision and correlation of the Cretaceous system of Sanshui basin are made through paleontological study on over 60 wells. The lower Cretaceous is called the Baihe formation. This formation is determined as of late Early Cretaceous (Aptian-Albian) according to the research on fossils of the plants, sporo-pollen and Charophyta. The upper Cretaceous can be divided into Sanshui formation and Dalang-shan formation. The fossil therein can be correlated with the typical sections (the Nanxiong formation and the Pingling member of Shanghu formation) of the upper Cretaceous in China. The Sanshui formation are comparable with the middle and lower parts of the Nanxiong formation. Their age is determined to be the early-middle stage of Late Cretaceous, whereas the Dalangshan formasion is comparable with the upper part of the Nanxiong formation and the lower part of the Shanghu formation, their age being considered to be the late stage of Late Cretaceous.