Abstract:In this study， D-glucosamine hydrochloride （GlcN·HCl） was combined with anhydrous magnesium sulfate （MgSO4） by complexation reaction to form complexes. The optimal pH was 6.5 determined through titration. To explore the mechanism of complex formation， the complexes were characterized by ultraviolet spectroscopy （UV）， infrared spectroscopy （FT-IR）， simultaneous thermal analyzer， and scanning electron microscopy（SEM）. The results indicated that the complex may be formed through the coordination reaction between the amino and hydroxyl groups in the molecule and the magnesium ion. After the formation of the complex， the crystal structure changed from a rhombic shape to a flat and elongated octahedral shape， and its thermal stability improved. Therefore， GlcN can form stable complexes with Mg2+ through complexation reaction to forming coordination bonds to prepare stable complexes， providing new resources for the prevention and treatment of osteoarthritis.