Using Chinese-fir powders as raw material and SO42——TiO2/clay solid acid as hydrolytic catalyst,the paper discusses the effects of solid acid quality,hydrolytic temperature,liquid-solid ratios and hydrolytic time on the yield of levulinic acid.Experiment results show that the optimal conditions for the preparation are: SO42——TiO2/clunch solid acid 3.5%,hydrolytic temperature 240℃,liquidιsolid mass ratio 18,and hydrolytic time 35min.Under these...