Due to higher expectations for health in recent decades, the issues of food preservation and safety are now attracting more and more attention. Therefore, research and development of food packaging materials is of important practical significance. While the wide use of functional plastic packaging brings great convenience to the food industry, serious problems also appear subsequently, such as source exhaustion, plasticizer transfer, and other potential food safety hazards, which pose great challenges to researchers. In order to overcome these shortcomings, the natural polysaccharide chitosan has emerged as a suitable food packaging material. Chitosan has many excellent properties such as biodegradability, biocompatibility, bioactivity, nontoxicity, and polycationic nature. This article reviews the discovery and preparation process of chitin and chitosan. In addition, the application of chitosan‐based films in food storage is highlighted. Finally, the future perspectives of chitosan are proposed.