Abstract: The water collected from upper coal mined area will pose a threat to lower coal mining in the multiple seams area.The paper analyzes the changes of hydrological conditions after the coal seam 2^-2 is mined in Nanliang coal mine and calculates the goaf water quantity.We find aquiclude between coal seam 2^-2 and 3^-1 is changed from 24.14 mto 40.37 m,it is less than the water suture zone's height of coal seam 3^-1(25.80～70.17m),therefore,goaf water of coal seam 2^-2 is the direct source of water inrush for coal seam 3^-1.