A fungus CQ31 isolated from soil samples was identified as Chaetomium sp.. This strain produced effectively xylanases utilizing several liguocellulosic materials in the solid-state fermentation (SSF), and corn straw was the best carbon source. The results of single-factor-experiment showed that the corn straw as the carbon source, tryptone as the nitrogen source, initial moisture content of 80% and initial pH 9.0 were the optimal conditions for xylanase production. Under the optimized conditions, it produced xylanase which was 4897 U/g dry substrate while mannanase was 803 U/g dry substrate after 7 days of cultivation. Therefore, xylanase and mannanase production by Chaetomium sp. CQ31 in SSF possess potential for commercial applications.