Abstract: Selecting some geological factors as independant variables， which impact on the inrush of ground water ， such as structure， mine stress， fracture， fault displacement， distance between fault and inrush point， thickness of water-proof layer and ground water pressure， the data at inrush points and uninrush zone as bases， introducing the theory of quantification I and II， quantifying the qualitative variables， implementing the calculation， the authors constructed the prediction model of inrush of ground water from floor in Jiaozuo Coal Mine ． After practical forecast tests， the model is proved to be reliable and useful for the prediction of water outburst．