Abstract: Based on the field surveys and repeated cross-profile observations of east coast in Wanning,Hainan Province,this study analyzed the status and causes of coast erosion.The east coast of Wanning has suffered erosion,the erosion phenomenon was mainly manifested in these aspects:erosion scarps,beach narrowing,beach lowing,beach erosion of marine aquaculture drainage and destruction of protection forest.There have three types of erosion:periodicity erosion,sustainability erosion and cliff erosion,cliff erosion is the most serious,the second is sustainability erosion,periodicity erosion is the lightest.Causes of coast erosion can be divided into two categories:natural factors and human factors.The natural factors include marine dynamic,typhoon and storm surge,sea level rise; the human factors include building marine aquaculture pond,cutting down the protection trees,mining uhligite and sand extraction in the foreshore.Although natural factors played an important role in the history of coastal erosion,human factors was the main reason of recent coastal erosion.