Abstract: Liposomes have been widely studied in drug delivery.However, the application of liposomes has been limited due to poor stability and other factors.Chitosan is a kind of cationic polysaccharide, which has excellent biocompatibility, biodegradability and bioadhesion, and can be chemically modified with better properties.In recent years, more attention has been paid for the study of liposomes coated with chitosan and its derivatives for drug delivery.Liposomes modified by chitosan or its derivatives can be improved in the aspect of their stability, adhesion, permeability, drug sustained release and cell uptake, and can be used to provide pH sensitivity on the drug delivery system under particular conditions.In this paper, research progress of the medical application of liposomes coated with chitosan and its derivatives in drug delivery system are reviewed.