Abstract: The ability of converting monosaccharide into ethanol by recombinant Escherichia coli KO11 was studied and optimized. Ethanol could be effectively produced by KO11 which fermented a wide range of monosaccharides including hexose and pentose,whereas yeast utilized hexose only. Under the optimum conditions of pH 5. 5,37 ℃and 150 r / min,the maximum ethanol yield was obtained up to 94. 81%( 20 g / L glucose) after KO11 was cultured in LB medium by agitating for 4 h and standing for 20 h,and up to 94. 15%( 20 g / L xylose) after culturing by agitating for 12 h and standing for 15 h. In addition,KO11 kept good performance at higher temperature( 43 ℃),which provides advantage for the simultaneous saccharification and fermentation processing.