The threedimensional damage constitutive relationship of coal is established and distribution law of the abutment pressure of the integrated coal beside the roadin packing for gobside entry retaining in fullymechanized caving face under the effect of given deformation of the main roof is analyzed by the damage mechanics theory. And the relationship between distribution of the abutment pressure and thickness of coal seam is explored. The presented result is of great theoretical significance and practical value to the study on stability control of the surrounding rock of roadin packing for gobside entry retaining in fullymechanized caving face.