Abstract: The grain size of sediment depends upon such factors as the transportation medium, transportation style and depositional environment. And the thick sediment deposited in the continental shelf areas since Quaternary is a result of paleo-environment evolution, such as sea level change and abrupt change in climate. All these features are reflected in the grain size characteristics of sediment. Basically, grain size parameters could be widely applied to analyze the characteristics of sedimentary environment, such as water hydrodynamics, sediment source and bottom characteristics. During recent years, the application of grain size analysis has been diversified due to the use of computer and simulation technology. Progresses have been made in areas like sediment transport patterns analysis using grain size trends of surface sediment in shelf seas, high resolution paleo-environment research using sensitive grain size of core sediment and reconstruction of ancient sea level using the partitioned grain size data.