The progress in studies of marine and continental Cretaceous of South China since 21 centuries is summarized in this paper. Cretaceous System of South China can be subdivided into 5 strata districts and 8 stratigraphic areas based on the different tectonic environment and stratigraphic features. Chronostratigraphic classification and bottom boundary stratotype of marine and continental Cretaceous of South China, and the boundary between Upper and Lower Cretaceous are briefly introduced, which are integral part of progress of global chrono- and bio-stratigraphic research. The author considered that the Southwest China and Tethys region marine Jurassic/Cretaceous boundary study is near the international level.