In this paper, the direction of the palaeostructural stress field of the Baisha syncline is determined by computing the reflectance ellipsoid of vitrinite in the coal samples, and it is found that it has no relations with the metamorphic zoning of coal. The author also presents a comparison of the grade of coal metamorphism with the structural features, the complicacy of structures, and the degree of coal deformation in several structures in the syncline. The research shows that the extension of isolines of coal metamorphism or coal rank intersects the syncline axis trace at a high angle; the metamorphism grade of coal strongly compressed is no higher than that weakly compressed ; the R0,max% isolines of vitrinite intersect the Qiyang epsilon-type structure arc; the metamorphism of tectonically strongly deformed coal (such as the mylonitic coal) is no higher than the non-deformed coal. Therefore, the grade of coal metamorphism in central-south Hunan is not directly related to the geologic structures.