The point pollution source environment treatment traditionally by taking an enterprise or a project as management object is more and more paradox to the regionalization of environment problems. Environment protection history and its implementation rationality demand new environment treatment model. Therefore, regional environment treatment system and mechanism combined by point pollution source environment treatment are demanded to be set up as soon as possible. Regional environment governance is the environment treatment model by taking natural region unity as the treatment object, and subregion governance and cooperative governance are its basic requirement and feature. Therefore, the organically associated unity of the four schemes such as environment subregion governance mechanism, regional environment entirety governance mechanism, regional environment cooperation governance mechanism and regional environment management system is needed to be built. The particularity of environment problems needs subregion treatment according to natural regions. Every natural region must be managed as a natural unity. Different natural regions and each administrative district in the natural regions must cooperate with each other, and the realization of regional cooperation needs to build effective regional environment management system.