Abstract: The paper used lithofacies statistical method to research the capped qualification of the capped coalbed stratum.Synthesis capped ability index(SCI) has been put forward to estimate the capped ability of coalbed gas quantificationally,and the capped ability of the capped stratum of the main exploited coalbed in the researching region was regionalized-forecasted.The research results indicated that the cap types of the researching region were kinds of from Ⅱ to Ⅳ,most regions belonged to Ⅲ which had the middle capped ability.In the western,southeast and the corner of northeast the researching region,there were rather strong capped ability,all of which belonged to Ⅱ,and other regions were the kind of Ⅳ.