In order to reveal the surface modification mechanism of fine coal by electrochemical methods, the structural changes of the coal surface before and after electrochemical modification were investigated by Fourier Transform In- frared Spectra (FTIR) and Raman Spectra. The results show that under certain electrochemical conditions, the oxy- gen-containing functional group in the coal structure and the oxygen content of absorption could be reduced and the floatability of coal improved. At the same time, the sulfur in the coal was reduced to the hydrophilic S2– which could be separated easily from coal. Thus electrochemical modification methods could be used to change the structure and func- tional group on the coal surface and to enhance the floatability of coal. In order to reveal the surface modification mechanism of fine coal by electrochemical methods, the structural changes of the coal surface before and after electrochemical modification were investigated by Fourier Transform In-frared Spectra (FTIR) and Raman Spectra. The results show that under certain electrochemical conditions, the oxy-gen-containing functional group in the coal structure and the oxygen content of absorption could be reduced and the floatability of coal improved. the same time, the sulfur in the coal was reduced to the hydrophilic S2- which could be separated easily from coal. Thus electrochemical modification methods could be used to change the structure and func- tional group on the coal surface and to enhance the floatability of coal.