Abstract: According to the structure features (amorphous carbon structure, high oxygen content and others) of the lignite, the paper introduced the analysis metho d of different oxygen functional group and carbon structure.The paper had an explanation and comparison on the chemical titration, Fourier infrared spectrum and X-ray diffraction spectrum analysis method.The paper in detail explained a FT-Raman semi-quantitative method to analyze the lignite and the derived semi-coke structure .Acc ording to the carbon structure features of the lignite and the semi-coke, the Raman spectrum was analyzed as 10 sub-peaks with certain physical meanings and the exp eriment showed that the method could effectively semi-quantitatively analyze the molecular structure information in the amorphous carbon structure.