Adeno-associated virus (AAV) is a single stranded DNA Parvovirus.AAV has been utilized as a therapeutic gene delivery vector and has proven safe and effective in human clinical trials.The advantages of recombinant AAV (rAAV) include long-term transgene expression, broad tissue tropism, non-pathogenic and its capability to infect both non-dividing and dividing cells.To develop targeted AAV vector for effective tumor gene therapy, two approaches have been explored based on the high homology among the capsid genes from 12 independent AAV serotypes.We first developed the targeted astrocytoma AAV vector using a "marker rescue" method on primary routine astrocytoma cells TgG(AZ)T121.After transduction of mutant capsids from different serotypes of AAV into TgG(△Z)T121 cells in the presence of adenovirus for isolation of the most efficient replicating virus, three variants were obtained.One of them named AAV12121 represented the recombination between AAV1 and AAV2 through several regions of homology and resulted in a novel capsid that demonstrated more efficient transduction on TgG(△Z)T121 cells than any natural AAV serotypes.