Yangtze River Delta plays an important role in China’s economic development，with the rapid economic development，Yangtze River Delta faces enormous pressure on the ecological environment，and the integrated features of ecological environment determine that Yangtze River Delta has to strengthen regional cooperation in environmental Treatment. The current development of Yangtze River Delta integration has been upgraded to a national strategic level，the process of regional integration of Yangtze River Delta is speeding up，and the inter-regional interdependence gradually increased，all these bring good opportunities to establish inter-regional environmental cooperation mechanism，optimize resource allocation，innovative environmental control technologies，and promote the process of environmental protection markets integration. In this context，the key fields of regional environmental cooperation include the overall planning of the regional environmental protection，construction of ecological compensation mechanism，sharing of regional environmental infrastructure，environmental protection industry development and market opening，the regional emissions trading markets，co-construction of ecological industrial parks，and low-carbon green intercity traffic.