Abstract: Castanopsis fissa and Schima superba are the two suitable and dominate tree species for fuel forest in the suburb of Wuzhou City in Guangxi Autonomous Region. Studies were conducted to find out the quantity of biomass in relation to site condition, density of crop and pure or mixed stand. The results are as follows:1. So far as site condition is concerned, the biomass of fuel forest at the foot of the mountain is the largest.2. So far as density of crop is concerned, in a certain range, the biomass increases with the increase of density of crop.3. So far as pure or mixed stand is concerned, the biomass of the pure stand of C. fissa per ha is more than that of the mixed stand, while S. superba is to the contrary.

Key words: Fuel forest, Castanopsis fissa, Schima superba, Biomass