Abstract: In order to effectively prevent great gas from goaf rushing into the coal mining face to cause the power cut-off and other accident, with the analysis on th e goaf gas emission law of No.4308 fully mechanized top coal caving mining face in Chengzhuang Mine, several measures, including the pipeline buried in the tailgate of the goaf, long boreholes in roof strike, the surface ground borehole drilling and others were applied to the gas drainage in goaf.The practical application showed that the above measures conducted could obviously reduce the gas from goaf rushing into the coal mining face, could make the gas content in the tailgate reduced by 46% and could increase the coal production of the coal mining face by about 25 000 t.Meanwhile a relative perfect goaf gas drainage system was established and a good ga s utilization access was formed to have a joint coal and gas extraction.