Chitosan is the only alkaline polysaccharide found in nature

due to its natural sources rich

biocompatibility

biodegradability

non-toxic

antibacterial strong and other good properties. Now

its broad-spectrum antibacterial has been widely recognized

but it’ s further application is limited because of its sparingly solubility in water. Therefore

chitosan derivatives has been one of the hot spots in the research of chitosan

which has been modified by some modification methods to improve its solubility. In this paper

several common hydrophilic chitosan modification methods and application of its derivatives in antibacterical fields were reviewed

which could provide the reference in the further activity study of chitosan.