Abstract: This research considered the contributing factors for coal bio-fermentation. The factors,which were evolved with fractures development,include the specific surface area of coal,and air permeation in coal cleats. The research analyzed the stimulating factor for anaerobic fermentation with fracture changes in different zones in coal seam. The ex- periment performed with coal fracture development and air permeation test which was done based on the gas flow ac- quisition system with two-dimensional loading set,coal anaerobic fermentation inhibition under air permeation test,and coal bio-fermentation response to the mesh size changes of coal. The data confirmed that the air permeation,which would be performed in the shallow zone of coal with the fractures development of coal and when the air concentration higher than 1% ,would be the key factor to inhibit the anaerobic fermentation of coal. Air transfused violently with fracture formed speed. Meanwhile,in the depth of coal where air concentration was lower than 1% ,the fermentation would enhance with specific surface area development. Facultative bacteria activity counteracts the repression of anae- robic fermentation inhibitory effect of oxygen in this zone.