In this study, chitosan, an aminopolysaccharide, was reacted with phosphazene-derived crosslinker by Schiff-base reaction to yield crosslinked-chitosan hydrogel. Here, hexakis(4-formylphenoxy)cyclotriphosphazene was used as a novel crosslinker agent with six reactive functional groups allowing the formation of bridges between polymeric chains. Amoxicillin, known effective bacteriostatic treatment, was used as a model drug to test the drug-carrying capacity of the gel and the antibacterial activity. Further, the acid-catalyzed aqueous degradation behavior of hydrogels was assessed in vitro. In conclusion, it is predicted that this newly obtained biodegradable hydrogel may have the potential to be used as a promising drug-carrying material in biomedical application fields.