The chemical compositions of two kinds of secondary biomass,auricularia residue and pleurotus ostreatus residue,were analyzed in comparison with their raw material.The pyrolysis of the three kinds of material was also performed.Compared with the raw material,the cellulose,hemicellulose,lignin contents of both the mushroom residues decrease significantly,and the content of ash increases.The change of chemical components not only lessens the yield of bio-oil,but also alters the component of bio-oil.The uppermost composition in the bio-oil from the raw material is cyclobutanol,whereas acetic acid or 2,2,6,6-tetramethyl-4-piperdone is dominant in the bio-oil from Auricularia residue and pleurotus ostreatus residue respectively.The selectivity of 2,2,6,6-tetramethyl-4-piperdone and 4-methyl-3-penten-2-one in the bio-oil from pleurotus ostreatus residue reached 35.3 % and 33.1 %.