Abstract: A method for indirect determination of reducing sugar in glucose injection by AAS was proposed in this paper. Reducing sugar was reacted with Cu2+ to precipitate Cu2O in a basic medium of pH 9.0-10.0. The precipitate of Cu2O obtained was dissolved in HNO3 and determined by AAS, and the amount of Cu2+ found was converted into contents of reducing sugar. Linear relationship between values of absorbance and mass concentration of copper was obtained in the range within 5.0 mg·L-1. Tests for accuracy and precision were made by addition of portions of standard solution to sample solutions at the concentration levels of 0.500 and 0.750 mg·L-1 and analyzed by the proposed method, giving values of recovery in the range of 98.0%-100% and RSD′s less than 4.0%.