Abstract: Quantitative monitoring of ecological quality changes and revealing the driving forces behind them are of great significance for ecological environmental protection and sustainable development. Taking Shanghai as an example, the ecological quality of Shanghai from 2013 to 2019 was analyzed by constructing the Remote Sensing Ecological Index (RSEI), and the spatial-temporal change of the ecological quality of Shanghai was studied by combining the transfer matrix. The driving factors affecting the ecological quality of Shanghai were analyzed by using the geographical detector. The results showed that the ecological quality of Shanghai changed significantly from 2013 to 2019, and the decline rate of RSEI is 17.19%. Socioeconomics, human activities and natural environment all had strong impacts on RSEI. In the single-factor detection, population density had the greatest impact, and the interaction of the two-factor detection was stronger than that of the single-factor detection. The research results can provide theoretical support for ecological environment protection in Shanghai.