 Cationic polymers are a type of non-viral nucleic acid delivery system that have been used to increase the efficiency of nucleic acid uptake by cells. These polymers are composed of positively charged groups that allow them to concentrate nucleic acid molecules into nanoparticles, allowing them to cross cell membranes more easily than other types of nucleic acid delivery systems. Biodegradable cationic polymers are particularly useful because they degrade over time, reducing the risk of side effects from long-term exposure to foreign materials. This paper provides an overview of cationic polymer research, focusing on biodegradable cationic polymers in particular. This article was authored by Siaming Kai, Rui Dou, Chen Guo, and others.