Abstract: Populus sp. is a fine variety with wide adaptability, male without catkins, fast-growing, high yield and enduring barren. However, pests damage the production and quality of this wood. To enhance insect resistance of Populus sp., Cry1Ac gene was introduced into poplar via Agrobacterium-mediated transformation with explants of leaves and internodes. The integration of the target gene into the poplar genome was identified by PCR and Southern blotting analyses. Real-time PCR analyses indicated the expression of Cry1Ac gene in seven transgenic poplar plants. Resistance evaluation by raising insect with detached leaves showed that 2 of 7 transgenic lines were superior in Hyphantria cunea resistance. Transgenic poplar plants with insect resistance facilitate afforestation and extension of the variety.