Abstract: Four coal samples from No.6 coal seam in Haerwusu mine were analyzed using fourier transform infrared spectroscopy(FTIR).Information about the type and content of functional groups in the samples were obtained after curve-fitting analysis.The results showed that benzene ring-disubstituted was the primary structure of aromatic hydrocarbon; contents of methylene, methyl and methenyl decreased successively, and it indicated that the coal contained a great number of alkyl side-chains, and the degree of branching chain was high; the main existing form of hydroxide radical was self-associated hydroxyl bond; the content of ether group was the highest among the three oxygen-containing functional groups, namely carbonyl, carboxyl, and ether groups.Meanwhile, the results showed that the change of structure parameters obtained from the FTIR has the close relationship with the first coalification jump through the study of correlation between the max reflectance of vitrinite (R_omax) and the structure parameters obtained from the FTIR.