Abstract: With the development of modern oceanic obser vation technologies,coastal survey data have experienced a substantial growth.The integration management of the data from different disciplines,different sources and different formats has become a major research field in coastal geomorphology by using geographic information system (GIS).A new methodology framework of GIS technology is put forward in coastal ocean geomorphology,including data acquisition,process,analysis,and representation.It focuses on some major GIS technology to study the land-ocean interaction mechanism,such as spatial analysis,submarine topography model and three-dimensionol (3-D) visualization,and apply its result to coastal urban planning,harbor site selection and geomorphological environment about coral reefs and islands on the continental shelf.The case studies cover the whole coastal ocean to serve the social community,economical development and diplomatic rights for decisionmaking all round in the coastal zone.The research shows clearly that the application of coastal multisource geospatial platform has changed the traditional coastal geomorphological science dramatically from its research scope,fields and methods,however,as made clear,extracting accurate information from remotely sensed data and GIS databases for coastal geomorphological applications is a nontrivial challenge that requires the combined knowledge and skills of information scientists and geomorphologists.