The environmental protection cooperation in the Yangtze River Delta stemmed from the regional economic cooperation and development framework and has lasted for almost 20 years. Especially since the establishment of regional air pollution cooperation mechanism in early 2014 and water pollution cooperation mechanism in the end of 2016，the regional environmental quality has been significantly improved. In November 2018，President Xi Jinping officially announced the regional integration development of Yangtze River Delta as a national strategy at the China International Import Expo held the first time，which shall give the Yangtze River Delta an unprecedented development opportunity. However，at present，the environmental protection cooperation in the Yangtze River Delta still has some problems on the implementation of the coordination mechanism，the information sharing mechanism，the cross-border management，and the integration of regional development planning，etc. How to further deepen and optimize the environmental protection cooperation in the Yangtze River Delta in the future？ How should Shanghai，as the bridgehead of the Yangtze River Delta，fully take the lead and promote the high-quality development of regional integration in the Yangtze River Delta？ This article will discuss the above issues on the basis of reviewing Shanghai’s participation in the regional environmental cooperation process.