Chitosan hydrogel wound dressings are biocompatible,biodegradable,antibacterial and hemostatic biomaterials.However,applications for conventional chitosan hydrogels are limited due to their poor solvability and mechanical properties in wet conditions [1].In this study,a citric acid modified chitosan (CC) derivative was synthesized via ethanol mediated condensation reaction.Such a CC derivative is soluble in an aqueous solution and can be transformed into a hydrogel by a freezing and thawing treatment.