Tongzi is one of the most important area of coal in Guizhou Province. According to the geological information of Jingtian coal mine in Tongzi, by systematic analysis, the indicator seam is built up. By analysis the characteristics of the indicator seam B₁-B₅, geophysical characteristic and coal seam characteristic, the method and characteristics of coal bearing stratum comparison and division in this area is narrated, the significance and function of Jingtian coal seam and indicator seam characteristics is summarized.