There is a great difference in the vitrinite reflectance anisotropy between the allochthon and autochthon of the nappe structure in the Huaibei Coalfield, Anhui province, which reflects different states of stresses and strains. The dip of the minimum reflectance (R_c) in the allochthon turns from NNW to WNW, indicating the state of stresses in the frontal zone of nappe. Most of the reflectance indicatrix are prolate ellipsoid, implying a lateral extensional strain during thrusting. The dips of the minimum r...