Trichosporon fermentans(TF)was domesticated to improve adaptability in fiber hydrolysate.Fermentation system from fiber hydrolysate by the domesticated TF have been optimized.By the flask experiments of several single conditions which affect TF growth and fat synthesis,the optimal fermentation conditions were studied.After domestication,the transform rate of sugar increase 37.2%,the biomass increase 24.3%,lipid content increase18.3% and lipid concentration increase 45.6%.The optimum fermentation conditions which were determined on the basis of a single test to be as follows:concentration of sugar,60~80 g/L,pH 6.0,quality ratio of yeast +(NH4)2SO4 3∶1.On the optimum condition,the biomass,lipid content and lipid concentration is 22.6 g/L,46.3%,and 10.5 g/L,respectively.At the same time,the composition of bio-oil was analyzed.