An action of surface wave at the Bien Dong (East Vietnam Sea) in NE monsoon is the main calise of features of erosion and accumulation along the coasts of Vietnam. Based on the theory of wave impact and the survey-study of some projects, especiall project KHCN.06.08 has built the "Map of coast and estuary fluctuations" with resolution 1/100.000 (33 pieces) in which shoreline of Vietnam is divided into five sections for analysis, each section contains features on the relationship between forces and geographical factors make the state with the characteristics of the erosion accretion and changes in the bank and also create local natural very intense and serious events, for every costal pieces.