Abstract: In order to improve the prediction accuracy of the coal and gas outburst in mine,measurements were conducted on the initial gas emission velocity of the anthracite coal,coking coal and long flame coal with different moisture contents after dry treatments.The results showed that the moisture would all have the influences t 0 the gas initial emission velocity of the anthracite coal,coking coal and long flame coal.The higher moisture content of the coal samples in different ranking coal,the low er initial gas emission velocity would be.The gas initial emission velocity would be decreased with the moisture content increased in index.The gas adsorption value of t he coal sample with the moisture reduced was the fundamental causes to reduce the gas initial emission velocity. The moisture content would have highest influences to the gas initial emission velocity of the anthracite coal,the medium influences to the long flame coal and the lowest influences to the coking coal.The reason was the diff erent pore features of different ranking coal.