Cecropin B is an anti-bacterial peptide of insect. Ce-cropin B can strongly inhibit the growth of rice bac-terial pathogens in vitro, such as Xanthomonascampetris and Xanthomonas oryzicola.Therefore,cecropin B gene has been regarded as a candidate forrice anti-bacterial genetic engineering.Using microprojectile bombardment, palsmidpCB1, a cecropin gene expressional vector carrying aselectable marker gene(bar gene)and a chimeric ce- Cecropin B is an anti-bacterial peptide of insect. Ce-cropin B can strongly inhibit the growth of rice bac-terial pathogens in vitro, such as Xanthomonascampetris and Xanthomonas oryzicola.Therefore, cecropin B gene has been regarded as a candidate forrice anti- bacterial genetic engineering. Using microprojectile bombardment, palsmidpCB1, a cecropin gene expressional vector carrying a selectable marker gene (bar gene) and a chimeric ce-