There are many middle and small types of basin in China with abundant coal bed methane resource, PetroChina has made breakthough of coal bed methane exploration in some basins. This paper summarizes the result from coal bed methane exploration in middle and small types of basin with high coal rank, middle coal rank and low coal rank, and puts forward special theories of coal bed methane accumulation and forming-pool in different middle and small types of basins. Author also analyzes coal bed methane geological characteristics and forming-pool conditions in high coal rank coal bed methane field of Qinshui basin, middle coal rank gas-bearing area of Ningwu basin and low coal rank gas-bearing area of Shaerhu basin. The research testes and verifies these theories mentioned above. In the end, this paper points out the coal bed methane exploring direction in middle and small types of basins in the future.