Abstract: The Bohai Sea is a semi-closed shallow shelf sea,consisting of three bays,one strait,and one basin. The geomorphology of it is discussed on the basis of the newly acquired data from a series of regional marine geological survey in recent years in addition to the data from previous works. A geomorphic classification system including 8 categories of Ⅲ-grade geomorphic types and 3 kinds of IV-grade geomorphic shapes is established according to the distribution of sediment types,river transportation,and the influence of the longshore current and waves on the coastal zone.