4.12%。Using seven types of biomass as raw materials, such as Chinese fir sawdust, corn stalks, rice husks and so on, experiments of biomass vacuum pyrolysis to prepare bio-oil were carried out in the home-made vacuum pyrolysis device. Seven kinds of bio-oil yields are more than 55%, and the bio-oil yield from Chinese fir sawdust is more than 67%. Component analysis results show that bio-oil is a kind of organic compounds with higher oxygen content. The major chemical components of seven kinds of bio-oil are similar, but large differences are in their relative contents. The phenol and phenol derivatives content in the bio-oil from Chinese fir sawdust is up to 72.81%. The bio-oil from Chinese fir sawdust contains eugenol whose relative content is 4.12%.