Abstract: Some following conclusions coal-forming material,ronk （maturity）,mineral and the evolution of the physicial or chemical structure of the thermally altered coals one reached by means of i. R.,Rock-eval and XRD. The coal forming material of Taiyuan Formation in Nanpiao had some algae and bacteria.Demineralization by coal treatment makes the aliphatic structure low temperature oxidation. The effect of the mineral in thermally altered coals on the S₂ peak con’t been neglected. T_max,TPI,OPI,d₀₀₂ and L_c are better maturity parameters,but HI,A factor,C factoy and the ratio of the aliphatics to aromatics are depended both on the type of the organic matter. d₀₀₂ and L_c one related with temperature as wall as heating rate. The reflectances of vitrinite are mainly deperded on the ement of arrangement of the polycyclic aromatic hydrocarbon. The reduction of L_a,L_c and L_a/L_c more than one are the characteristics of the thermally altered coals. The evolution of the physical or chemical structure of the thermally altered coals is different from that of the geothermal metamorphic coals,but is similar to that of the telemagmatic metamorphic coals.