As a staggered zone of land and sea system, the ecological function of coastal wetland is increasingly significant.However, in recent years, in order to maintain the rapid economic development, developed coastal cities have carried out large-scale reclamation and development, which has seriously compressed the ecological space of coastal zone. Taking the Dongtan wetland in Nanhui, Shanghai as the research object, Landsat remote sensing images were taken from 4 issues in 2000, 2006, 2012 and 2018, and based on the remote sensing ecological index(RSEI)to monitor and evaluate the ecological pattern of the research area in an objective，quantitative and visual way. Results show:(1)The mean of RSEI in 2000，2006，2012 and 2018 is 0.295, 0.227, 0.405 and 0.489. After the classification treatment, it was found that the ecological environment quality in the study area rose from “poor”to “good”, and both “excellent”and “better” increased, which shows the ecological environment quality of the Dongtan wetland was slightly improved.(2)According to the image differencing method of RSEI between 2000 and 2018, the area proportion of the eco-environmental status in the study area of “degradation”,“no change”and“improved”is 12.41%,53.32% and 34.27%, and main body is“nochange”.(3)The RSEI has suitability to Dongtan wetland. Through the visual expression of the change of ecological pattern, the ecological evolution process of urban coastal wetland can be better revealed, and avoid some ecological risks，to achieve sustainable development of cities and scientific management.