Identifying typhoon sequences on large time scales is of great scientific and practical significance to predict the super typhoon activities in the future.Although the high frequency of typhoon occurrence in Hainan Island in history is well known,it is difficult to determine the frequency of occurrence of the rare events like the Rammasun typhoon because of lack of detailed historical records.Here we use the sedimentary record,in combination with the information on the present-day events,i.e.,the Rammasun typhoon,to define the typhoon intensity and identify the super typhoons that occurred in the past.A detailed field investigation was conducted in the coastal area near Wengtian Town,northeastern Hainan Island.We discovered storm beach-rock boulders and storm over-wash sediments interbedded within the coast dune sequence on the northeastern coast of Hainan Island.Base on laboratory and sediment dynamic analyses,we propose that the deposits were generated by super typhoon events,perhaps as early as 3 400 aBP.We find that the intensity of the typhoon that created these deposits was stronger than the Rammasun typhoon,which is of great significance to the reconstruction of typhoon sequences on millennial/centennial scales.Hydrodynamic analysis indicates that the wide reef flat in front of the beaches and coastal dunes plays a significant role in coast protection.Thus,the regional coral reef degeneration that is taking place now,together with likely intensified storms in response to climate change and future sea level rise,will become an enhanced risk of coastal erosion.