The lateritic weathering crust developea oh the basaltie tableland are widely distri-buted in the northern part of the Hainan island. Aceording to the periods of basalticeruption call be distinguished into three main weathering stages, i.e. the Shimaolin(Middle Pleistocene), Huguanguan (Late Pleistocene), and Leihulin (Holocene)stages. From them only in the Shimaolin one the red earth has formed.