Abstract: The catalytic reaction solution used for preparation of glucosaminic acid was mixed with NaNO2 as derivatizing reagent, and derivatized for 5 min at 25 ℃. The solution containing derivatives of glucosamine hydrochloride and glucosaminic acid was used for HPLC analysis, using Aminex HPX-87H ion replusive column as stationary phase and 5 mmol·L-1 H2SO4 solution as mobile phase in isocratic elution. Differential refractive index detector was adopted in the determination. Linear relationships between values of peak area and concentration of the 2 compounds were obtained in the same range within 50 mmol·L-1, with detection limits (3S/N) 0.014 mmol·L-1 (for glucosamine hydrochloride) and 0.034 mmol·L-1 (for glucosaminic acid). The proposed method was applied to the determination of glucosamine hydrochloride and glucosaminic acid in catalytic reaction solution, giving values of recovery in the ranges of 99.3%-100% and 99.2%-102% with RSD′s less than 2.5%.