Abstract: In order to have a correct and full understanding on the parameters of the coal bed methane,the injection,the pressure drop method and the hydraulic fra cturing method was applied to the test and measurement on the parameter of the coal bed methanereservoir.The reservoir pressure and the ground stress parameters 0 f 83 reservoirs in 55 wells in the south part of Qinshui Basin were obtained. The distribution law of the coal bed methane reservoir pressures in the south part of Qinshui Basin and the control factors of the structure stress,buried depth,ground stress and others were studied.The study results showed that the pressure of the coal bed met hane reservoir in the south part of Qinshui Basin would be mainly the low pressure reservoirs.In the several blocks of the south part in Qinshui Basin,the reservoir press ure gradient of the Zhengzhuang Block would be the highest,the Shizhuang Block and Fanzhuang Block would be the second and the min reservoir pressure gradient W ould be Daning Block and Panzhuang Block.The structure stress,buried depth,ground stress and underground water mineralization would be the major factors to control the reservoir pressure.