The plant expression vector pBin438Vip3A was constructed and transformed into cotton variety “Jihe 713” by agrobacteriummediated transformation. A new insectresistant gene, Vip3A, was introduced into cotton plants to create new transgenic cotton germplasm resistant to cotton bollworm. The results showed that: (1) Vip3A gene has been transformed into the cotton genome and can be inherited stably. (2) In laboratory, two transgenic lines exhibited high resistance rate to bollworm, and three transgenic lines did resistance rate compared to the control. (3) Based on Southern blotting analysis, the transgenic line BV01 contained a single copy of insertion. (4) According to the results of Elisa, the foreign Vip3A gene was expressed in root, stem, leaf, flower and seed of BV01. Moreover, there were significant differences in Vip3A protein contents of the functional leaves among different stages, in order from high to low: seedling stage, bud stage, anthesis stage, boll stage and bolling stage. In this study, we successfully introduced the Vip3A gene into cotton plants, which possessed high resistance to cotton bollworm, laying a solid foundation for breeding new cotton cultivars with high resistance to cotton bollworm.