In recent years, urban wetland parks are developed rapidly, but there are few theoretical researches on urban wetlands. So the theoretical researches are demanded urgently to maintain the health and sustainability of urban wetland parks. As a new concept emerging from landscape ecology and ecosystem health, landscape health is the subject dealing with ecosystem health on the scale of landscape. Several theories and methods, including the theories of geography, landscape ecosystem, environmental science and the methods of RS, GIS, geostatistical analysis and modeling, were used to study the theory of landscape health in urban wetland park. Considering the characteristics of urban wetland parks, landscape structure health and landscape process health were applied in landscape health assessment based on the landscape functional classification, and a case study was done in Xixi Wetland Park. The main research findings include: 1) the area of very good health and good health landscape mainly distributed near the center of the park, covering 23.63% of the whole park; and 2) the area of ill health and diseased landscape accounted for 41.39% of the park and distributed near the surrounding area of the park. Based on the study of landscape health, many suggestions were provided for the management of the park, including reducing human disturbance, adjustmenting landscape structure, and maintaining the water quality in the wetland park.