Abstract: This paper introduced principle of geo-stress test by hydrofracturing This method was applied at 8 test points in east and west mining area of Zaoquan Colliery Test results were as follows Horizontal stress was major in this area Maximum horizontal principal stress was 8.6～13.37MPa,its direction was north-to-west Angle between maximum principal stress direction and roadway axial direction was 50～68° in east mining area,and that was 4～70° in west mining area and increased with roadway inward Geo-stress value of this area was medium low Maximum and minimum principal stress totally increased with roadway inward