Abstract: Several kinds of powder chitosan salts were prepared by half-dry grinding method.Film-forming properties,antibacterial capacity and egg fresh keeping capacity were investigated.Infrared spectroscopy shows that two reactants connection is not simply physical absorption,but protonation reaction of chitosan occurred in solvent-free conditions.Therefore,the products were soluble in neutral water and the stability was increased during the storage.This preparation method is ease,sanitary and economic.Fabrication and performance test of membrane,antimicrobial test and preservation test showed that chitosan lactate and chitosan acetate can be used as antistaling agent,which is simple,convenient and effective.