Abstract:Emergy wastage of fossil energy and the emergy that agricultural residues can substitute were calculated based on the statistical data during 1953 to 2007. The emergy of agricultural residues could almost compensate for that of fossil energy consumption in the early China. However, the disparity of emergy between wastage of fossil energy and agricultural residues supply was getting huger along with the society and economic development. The emergy that supplied by agricultural residues only accounted for 10.35% of which that the fossil energy consumption in 2007. It could reduce much environmental value loss if fossil energy were substituted by bio-energy. The reduced environmental governance cost was 773.91×108 yuan because of reducing coal mining and the environmental value loss because of fossil energy consumption was 11311.76×108 yuan from 1990 to 2007. Among them, the environmental value loss because of reducing sulfur dioxide emission was the most, which accounted for 56.93%. The environmental value loss because of reducing nitrogen oxides and ash emission respectively accounted for 33.13% and 9.94%.