Abstract: Water inrush in coal mine area is a sudden phenomenon,which results in accidents,makes miner die and mine well unsafety. Being based on detecting out recharge condition,it is necessary to solve the problem of water inrush factors allocation. At the past,it was very diffcult to decide this problem quantitatively. We have applied the tool of information analysis,made size of water inrush factors acting on rockmass expressed by relative information measure quantity as information unit.So,an effective tools is Provided for water inrush factors analysis in this paper.