Abstract: Based on considerable borehole and production data, a trend-surface analysis has been undertaken on the space distribution trait of the Permian seam 13-1 in the target area, and also the method of orientation variability was proposed to study the stability of No.13-1 coal seam. The results show that the shape of No.13-1 coal-seam floor is higher in northeast and lower in southwest; the thickness of coal-seam is thickened from northeast to southwest, and the thick and thin coal-seam distribute interlace following the inclination of coal-seam; the stability is becoming better along north-south, and the compatibility of comprehensive mining is also becoming better.