Abstract: In order to provide design reference for 4-1 coal-seam mining of Guoqiang colliery,stress characteristic of coal pillar influenced by gob-side abutment pressure,roadway-side abutment pressure and compression stress of overlying strata after full-mechanized caving mining was researched by setting up a mechanical model.Results showed that plastic area width at gob-side was related with geo-stress,stress concentration ratio,inner friction angle,cohesion and mining height and that plastic area width at roadway-side was related with geo-stress,working resistance of powered support,roadway radius and inner friction angle and cohesion of coal.On the basis of this,physical and mechanical parameters of coal pillar were obtained by experiment.Geo-stress was obtained with stress relief method by overcoring.Optimized coal pillar width was 15.4m~23.1m for 4-1 coal-seam of Guoqiang Colliery.