A plant expression vector pBACG containing the DNA sequence coding for Amaranthus caudatus agglutinin (ACA) and a modified Glanthus nivalis agglutinin (GNA) gene was constructed. Leaf explants of Nicotiana tobacum cv. SRI were transformed with A. tumefaciens LBA4404 harbouring the above expression vector. Results from PCR and Southern blotting analysis showed that both the ACA and GNA gene were inserted into the genome of transformed tobacco plants. Western blottingting analysis of soluble protein isolated from transgenic plants showed that ACA and GNA were synthesized. The results from insect bioassay with peach aphids ( Myzus persicae) revealed that the transgenic plants of pBACG had acquired high resistance against peach aphids. The average aphid-inhibition rate reached up to 83.9% and 85.3% for transgenic plants (T0) and their selfed progenies (T1) respectively,indicating that the functions of these two genes were inheritable.