Abstract: Chitin was prepared from fresh and dry lobster shell with average yield of 4.1% and 18.2% respectively. D-Glucosamine hydrochloride(D-GclN•HCl) was made from chitin with average yield of 53.9% and the purity of 98.6% . The effect of concentration of hydrochloric acid, and its hydrolytic time on the reaction was invesitgated at the same time. The product was confirmed by TLC,IR,MS and elementary analysis. The compound has two mp of 197.195℃ and 217.857℃. Δ H value is 666.481J/g. Theα27D is +72.18°.