Abstract: The evolutionary history of South China Sea can be summarized as a series of events of micro-plate pulling and thinning, cracking, slipping, rotation, convergence and collision under the influence of the movement of the Pacific Plate and the Indian Ocean Plate, through some critical evolutionary periods as 55 Ma, 33 Ma, 25 Ma, 16 Ma, 6 Ma, 2 Ma. There are lack of studies on long term sea-level changes and coastaline changes in the region of SCS. Based on the study of coastal depositional facies and paleobathymetry from the drilling data of SCS basins, we reestablished the paleocoastal line for each critical geological time since Paleocene. Comparison was made with the coastaline changes in the periods of Paleocene-Eocene thermal maximum, Eocene -Oligocene global climate cooling event, Oligocene-Miocene global cooling, sea-level fall event, Middle Miocene climate warmer global sea level rise events, Early Pliocene global warming event, Late Pliocene Arctic ice cap formation event. Environment evolution of the SCS since Paleocene is further described.