Some inducible antibacterial peptide (AP) were developed from the haemolymph of Chinese oak silkworm,Aniheraea pernyi pupae.The AP had broad-spectrum inhibition on bacteria such as wilt disease,Pseudomonas solanacearum of tobacco etc.The AP-D has been isolated and its amino acid sequence has been determined (36 peptides).We designed the nucleotides sequence of AP-D gene (122 bp) and synthesized by by DNA synthesizer.The M13 mp8 DNA was ligted with AP-D gene and transformed into E.soft JM103.The recombinant plasmid cut with Sai 1 and co24 plasmid containing CaMV 35S promotor cut with Xho I were ligated and transformed into Agrobacterium tuonefaciens by triple mating method.A Selected medium containing Km,Cm,Spc and Str was used to select the colonies which bad insert with AP-D gene.A.turnefaciens containing AP-D gene was used to infect the leaf dics of tobacco.After 4 weeks,we found some plantlets differentiation at the redges of leaf dics.These plants were resisted to Km,the nopaline detecton and Southern blot hybridization with AP-D gene probe showed that AP-D gene had been integrated into tobacco plant.The expression product should detected with its monoclonal antibody.We are now studying this in order to introduce the AP-D gene into to bacco plant.