The method of gas chromatography has been set up under laboratory condition to de-termine the content of pentosan(as index with arabinose and xylose)in rice bran. The eightisomers of pentose and hexose were separated and determined and their standard curveswere also made. In the meantime, the accuracy, recovery rate and stability of this methodwere analysed. The results showed that this method had high - sensitivity(standard sample0. 05 mg / kg), high - speed(8 standard samples determinded for 15 min) , sim...