Abstract: In order to solve problems of ecological treatment in suburb mining subsidence seeper area，the characteristics of suburb mining subsidence damage and the requirement for city development are comprehensively analyzed.Taking construction of Tangshan Nanhu artificial wetland as a case，some issues including unstable water areas，lack of water resource and water pollution during the construction processes of artificial wetland are solved，and lake is enlarged to form stable wetland area.Water balance analysis indicates that the construction of artificial wetland provides reliable water resources.The water holding ability can be improved by adopt such technical measures as plugging the sewage draining，landscape greening on wastes，internal water cycling models in wetland.So，ecological environment in south mining subsidence area of Tangshan is profoundly improved.The research results provide a reference for ecological treatment in similar suburb mining subsidence seeper area.

Key words: Tangshan Nanhu wetland, Mining subsidence seeper area, High underground water, Water holding ability