Adeno-associated virus(AAV)belongs to the family of Parvoviridae. It is a small virus which can infect humans and some other primate species with extensive host cell and low-immunogenicity. Besides, modified AAV can target the specific tissues and cells effectively. As a kind of gene therapy vector,Adeno-associated virus have been widely known of its biological characteristics. By modification of the adeno-associated virus serotype and structure of capsid protein, we can extend the application range of AAV vectors. This article introduces the targeting mechanism and results of some related researches, the genetic engineering modification of AAV capsid proteins, the transcription regulation modification of target gene expression, and gene modification and the covalent coupling of AAV capsid proteins.