Abstract: As a deacetylation product of chitin, chitosan is the only basic cationic polysaccharide. It has been widely used in the medical field, such as wound healing, drug carriers, and tissue engineerin, because its good biocompatibility, non-toxicity, low sensitivity and biodegradability. Based on the biological characteristics of chitosan and its derivatives, this article will review the application and research of chitosan in the following ophthalmic subspecialties: sustained release of drugs for ocular surface diseases (such as eyelid defects, dry eyes, keratitis, corneal wound healing, corneal tissue engineering); chitosan coating complex liposome which can delay cataract formation, sustained release of antimetabolite from chitosan nanoparticles modified intraocular lens to prevent posterior capsule opacification(PCO); anti-glaucoma drug sustained release for glaucoma treatment and anti-scarring drug sustained release post filter surgery; chitosan oligosaccharides’ effect in experimental autoimmune anterior uveitis; retinopathy (insulin sustained release for diabetic retinopathy, a kind of new scleral buckling material for retinal detachment, and chitosan oligosaccharides prevent retina from ischemia-reperfusion injury). However, most researches are in vitro or animal experiments, and there are no large sample size and rigorously designed long-term clinical trials. (Int Rev Ophthalmol, 2020, 44： 105-111)