Abstract: Hyaluronic acid (HA) possesses excellent biocompatibility, biodegradability, and non-immunogenicity, and exhibits active targeting capability to receptors such as cluster of differentiation 44 (CD44). Therefore, HA has become an important material for the design and preparation of drug delivery carriers in recent years. HA is rich in functional groups that can be chemically modified, but different modification methods and sites can affect its biological properties. This paper summarizes and discusses the effects of chemical modification on the biological properties of HA based on the formation mechanisms of such properties, as well as the derivatization and characterization methods of HA, so as to provide some reference for rational research on chemical modification of HA.