AAV-ITR gene expression mini vector is a double-strand or single-strand DNA that only contains inverted terminal repeats of adeno-associated virus, cis-elements and gene of interest and does not contain any other foreign DNA sequences. We prepared Bac-ITR-EGFP and Bac-inrep. Spodoptera frugiperda cells were infected with Bac-ITR-EGFP (P3) and Bac-inrep (P3). Up to 100 μg of AAV-ITR-EGFP gene expression mini vectors were extracted from 2 x 10(7) cells of Sf9 72 h after infection. The gel electrophoresis analysis shows that most forms of AAV-ITR-EGFP gene expression mini vector were monomer and dimer. The mini vector expression efficacy was examined in vitro with HEK 293T cells. The EGFP expression was observed at 24 h after transfection, and the positive ratio reached 65% at 48 h after transfection.