In an effort to promote the sustainable utilization of waste biomass resources, the effects of biomass residence time and temperature on the fast pyrolysis yield, higher heating value (HHV), and gaseous composition were explored. Rice straw, corn stover, and its pyrolysis yields were analyzed using proximate analysis, ultimate analysis, and gas chromatography. Bio-oil yield of different biomass was characterized. Increase in biomass residence time favored bio-oil yield, gas yield, and HHV of char. Results showed that increase in fast pyrolysis temperature up to 500 degrees C increases the bio-oil and gas yields while the char content decreases. Above 450-500 degrees C, a sudden increase in gas yield was observed. HHVs of bio-oil and char were favored by increase in temperature up to an optimum value. Pyrolysis temperature had a pronounced effect on gas composition. Increase in temperature favored H-2 and CH4 concentration.