Abstract: Toluene conversion over packed bed of biomass char with microwave heating was determined. The effects of charring conditions, such as temperature, activation methods and precursors, on toluene decomposition characteristics were determined. The results showed that toluene conversion over biomass char was obviously influenced by charring conditions. Higher charring temperature could enlarge the surface area and pore volume of biomass chars and also enhance toluene conversion on biomass chars. Toluene conversion could reach 99.9% over biomass char which was prepared at 850℃. Surface area and catalytic activity of biomass chars were increased when it was activated in CO2 or steam atmosphere. Mineral contents strongly influenced the catalytic activity of biomass char. In comparison to the catalytic activity of rice husk chars with and without deash, it was revealed that the more K2O and CaO biomass chars had, the better catalytic activity they showed.