Modification of metallurgical coke,biomass char and semi-coke was carried out using a microwave device with power of 450-850 W and irradiation time of 6-12 min.The desulfurization rates of three carbon materials before and after modification were tested.The effects of microwave power and irradiation time on the pore texture and surface chemical characteristics of the three carbon materials were examined by SEM,BET and Fourier transform infrared spectroscopy(FTIR).The results showed that the specific surface area,total pore volume and pore diameter of biomass char and semi-coke after irradiation decreased slightly.Noteworthily,the pore diameter turned small and the acidic functional groups on their surface decomposed,thereby the basicity of carbon surface increased by microwave modification.The optimal promotion of desulfurization rate of three carbon materials was semi-coke irradiated at 850 W for 9 min and the sulfur dioxide adsorption rate was up to 45%. Modification of metallurgical coke, biomass char and semi-coke was carried out using a microwave device with power of 450-850 W and irradiation time of 6-12 min. The desulfurization rates of three carbon materials before and after modification were tested. Effects of microwave power and irradiation time on the pore texture and surface chemical characteristics of the three carbon materials were examined by SEM, BET and Fourier transform infrared spectroscopy (FTIR). The results showed that the specific surface area, total pore volume and pore diameter of Noteworthily, the pore diameter turned small and the acidic functional groups on their surface decomposed, thereby the basicity of carbon surface increased by microwave modification. The optimal promotion of desulfurization rate of three carbon materials was semi-coke irradiated at 850 W for 9 min and the sulfur dioxide adsorption rate was up to 45%.