This paper studied on the growth, fermentation characteristics and ethanol tolerance of the strain identified as Thermoanaerobacterium saccharolyticum. The result showed that mannose, glucose and xylose were preferable to other carbon sources for its growth, while xylan and cassava starch could be consumed by the strain. Optimum concentration of substrate was 15 g/L. The ratio of glucose: xylose did not show significant influence on the growth. The highest tolerance on ethanol was 3% (V/V). Cultured on the medium of 5 g/L xylan, xylose and cassava starch for 60 h separately, lactic acid, ethanol and acetic acid were detected, and the ethanol concentration was 0.824, 0.867, 0.916 g/L, respectively.