Abstract: The evolution characteristics of chemical structure of experimental deformed coals under high temperature and confining pressure and tectonic coals is deeply approached through methods of X-ray diffraction (XRD),electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR).It is expounded that the change of vitrinite reflectance of deformed coals is a reflection of their chemical microstructures in physical character.The evolution of vitrinite reflectance of deformed coals is deeply affected by factors of stress and deformed environment and it really recorded characteristics of stress action and strain environment and so on in structural deformed history.Thereford,the vitrinite reflectance is one of the important indicators in research of coalfield structure.