Direct liquefaction of Cunninghamia lanceolata in water was carried out in an autoclave in the reaction temperature and time ranges of 280-360degreesC and 10-30 min, respectively, and three feedstock ratios of biomass/water were tested. The experimental results show that the yield of heavy oil has a maximum between 320 and 340degreesC, depending on the reaction time and the feedstock ratio adopted. At the experimental conditions of this work, the maximum heavy oil yield is about 24%, obtained at the feedstock of 8 g biomass and 100 ml distilled water, with the reaction time of 10 min and the reaction temperature of 320degreesC. (C) 2003 Published by Elsevier Science Ltd.