An efficient and stable cabbage transgenic system was established through the exploration of the factors affecting the Agrobacterium tumefactions transformation as well as the size and stage of explants.Six widely used cultivars were selected in this experiment.The hypocotyl segments from the sterile seedlings were used as the explants.Theexplants were infected with A.tumefaciens LBA4404 containing plasmidspBin-TI-19-2,in which constructed with two copies of the Cowpea Trypsin Inhibitor(CpTI)gene.The explants were screened on the medium containing kanamycin (50 mg/L).80% of the explants formed kanamycin-resistant callus,then differentiated into seedlings.One callus clump could forms 5 seedlings at minimum and 22 seedlings at maximum. The result of Southern hybridization with the kanamycin-resistant cabbages showed that the CpTI gene in the T-DNA had been fully integrated into the genome.The transgenic transformation efficiency reached to 20%.The insect-resistant test with Plutella xylostella（Linnaeus）demostrated that the resistance of the transgenic plants were stronger than the untransgenic plants.%通过对影响根癌农杆菌转化的多种因素的比较和探索后，建立了一种以农杆菌介导的高效和稳定的甘蓝遗传转化系统。选择目前在生产上大量推广应用的6个优良甘蓝品种，用其无菌苗的下胚轴作为外植体，经农杆菌LBA4404（含质粒pBin-TI-19-2）感染，在含卡那霉素50 mg/L的抗性培养基上筛选，80％的外植体表现出抗性，形成愈伤组织并进一步分化成苗。每块愈伤组织最低成苗5株，最高可达22株。对部分抗性植株的总DNA进行Southern杂交，结果表明T-DNA上的CpTI基因已整合到甘蓝基因组中，外源基因的转化频率高达20%。通过抗小菜蛾实验发现，转基因植株较未转基因植株有明显的抗性。
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