Abstract: In order to study the main controlling factors of coal adsorption capacity with different metamorphism, through microscopic component analysis, mercury intrusion test, liquid nitrogen adsorption experiment and methane isothermal adsorption experiments, the relationship between coal rank and adsorption capacity were d iscussed. The results showed that Rowas 0.44% ~ 3.20%, Langmuir volume was 9.11 ~30.24 m3/t, and Rovalue increased with the coal rank increasing in the study are a; the porosity values, the BET specific surface area, the micropore volume of coal samples presented a trend of high-low-high variation along with the rising of coal ran K, and attained the minimal value when Ro= 2.3%, the pore structure affected the adsorption space of the coal reservoir, but it could not lead to the change of the adsor ption capacity of the coal reservoir. The pore shape especially the ink bottle pore is stronger than others. The vitrinite content plays a certain role in the adsorption capa city of the coal reservoirs during the low coal metamorphic grade, in the high metamorphic grade, and the fusinite's control is stronger.