Abstract: Compared with traditional vaccines, nucleic acid vaccines can induce a more comprehensive and durable immune response, and are manufactured more quickly. Among them, mRNA vaccines can be precisely designed, with good tolerance and strong immune response. In comparison with DNA vaccines, the expression mechanism of mRNA vaccines is safer and simpler, showing great potential of broad application. However, since mRNA vaccines are unstable and can't easily penetrate cell membranes, it is critical to design delivery systems that can protect mRNA vaccines and deliver them to target cells. In this review, we highlight the features and research progress of lipids, polymers, peptides and other non-viral vectors and (or) delivery systems used for in vivo delivery of mRNA vaccines, and also give an outlook on the research prospect of mRNA vaccines.