The influence of oxidation of coal, performed with different oxidising agents, on the sulphur species was studied. Conversions of the sulphur species were investigated by the Atmospheric Pressure-Temperature Programmed Reduction method (AP-TPR). The removal of pyrite proved to be advantageous for AP-TPR analysis. It was found that non-thiophene sulphur species undergo easier oxidation by different agent then thiophenic structures.