Abstract:The hollow inclusion technique is used to measure the in-situ stress of coal and gas outburst mining area. The measurement sites lie in the Northeast,Middle and East China,which include 7 mining areas such as Fuxin,Pingdingshan,Hebi,and Huainan. Based on the analysis of measurement data from outburst mining areas,conclusions could be drawn as follow:(1) major principal stress and minor principal stress are horizontal stresses and the inter medium principal stress is vertical stress,and the type of stress field is the dynamic stress field;(2) the major principal stress and minor principal stress are higher than those of other regions;and the tectonic stress is outstanding;(3) the ratio of major principal to minor principal stress ranges from 1.56 to 3.93,in which 69% ranges from 1.7 to 2.8 and 50% is about 2.0;the subtract of major principal stress and minor principal stress is very salience;(4) the ratio of the major principal to the vertical stress decreases with the increase of depth. The stress field has the changing tendancy from dynamic to static. At last,the role of in-situ stress is discussed. The gas and coal strength are the main factors influencing coal and gas outburst. Gas pressure and gas content increase in high in-situ stress environment,so the impetus of coal and gas outburst increase. Because the coal strength(peak strength) decreases,so the resistance of coal and gas outburst decreases. As a whole,in high in-situ stress environment,the gassy coal tends to be instable and coal gas outburst occurrs as a result. In-situ stress plays a key role during the occurring and development of coal and gas outburst. The characteristic,of in-situ stress fields have an important function in coal and gas outburst.