Abstract: The current status of sea area use in coastal waters has become an important basis for sea area management and land reclamation.Based on the current status data of the national sea area dynamic monitoring and management system, the paper proposed the mining process of the current use data of the sea area by the spatial data mining method of GIS.Taking the coastal waters of Liaoning province as an example, the conclusions as following:(1) The potential usage of coastal waters in Liaoning was large, but there are still unidentified seas.(2) The fisheries were the main use type in coastal waters of Liaoning, and the sea using mode is mainly open farming.(3) The deep sea area have been used in the coastal waters, which were mainly bottom sowing.(4) The distribution of fishery in the coastal waters is concentrated, and the using mode is a regular band distribution pattern from land to sea.(5) The phenomenon of unconfirmed use of seas has been significantly reduced in Liaoning province, and the scale of deep sea bottom aquaculture has been expanding in the past five years.