Abstract: Nanchuan lean coal in which inorganic sulphur had been removed was used to investigate the effect of electrolysis conditions on organic sulphur removal from coal. The results indicated that the amount of sulfur removed in creases with time, but the removal rate becomes slower. When the concentration of HCl is lower than 3.2 M, the sulfur removal changes little; when it is 3.2 M～4.8 M, the sulfur removal is improved significantly. The higher concentration of coal slurry, the lower the sulfur removal rate. The desulfrization of organic sulphur is 18% for 0.05g/mL coal slurry in 10 h in acidic medium. Therefore, organic sulphur is more difficult to be removed than inorganic sulphur by electrolysis.