Coal is both a source rock and a reservoir rock.Reservoir characteristics and gas transfer behavior are its key factors to determine whether the economic development.Reservoir properties of coal are closely related to coal metamorphic rank.Pore structure,adsorption capacity and flow capacity have significantly difference resulting in the different characters of a high rank and low rank coalbed methane reservoir.This paper systematacially research on reservoir pore structure,adsorption/desorption and gas tra...