Abstract: Cotyledons with petiole from aseptic seedlings of Chinese cabbage (B． campestris ssp．pekinensis，cultivar‘Beijing 80’)were used as explants for in vitro transformation using Agrobacterium tumefaciens C58 carring plamid pBBBasta-pinⅡ-bar．Via series concentration selection of PPr．the transgenic
resistant plants were got，and showed high Basta resistance when transplanted to the greenhouse．It was proved that by shoot regeneration from young leaf disc of the survived regenerated plant，the chimera status
of the plants can be eliminated．Transgenic plants were confirm ed by PCR，PCR-Southern，and genomic Southern blotting which showed that the bar and pin Ⅱ genes were co-integrated into the plant genome．Continuous insect feeding trials using larvae of Pieris rapae L．revealed that larvae fed with transgenic leaf tissue had a higher mortality，and the developments of them were retarded compared with those larvae fed with nontransgenic control plants．

Key words: B．campestris ssp．pekinensis, Pieris rapae L．, Insect resistance, Proteinase inhibitor gene(pin Ⅱ), Chimera