Abstract: ObjectiveTo explore the effect of BAG-1 on lung adenocarcinoma cells radio-sensitivity through constructing high expression vector of BAG-1. Methods Total RNA was extracted from A549 lung cancer cell lines.BAG-1 gene was amplified by RT-PCR.The expression vector pcDNA3.1-BAG-1 was constructed，and then transfected into lung cancer cells A549.A549 cell lines with high expression of BAG-1 was selected by Western blot.Effect of BAG-1 on lung cancer cell radio-sensitivity was investigated by cloning experiments. Results The high expression vector of pcDNA3.1-BAG-1 was constructed successfully.High expression of BAG-1 decreased lung adenocarcinoma cells radio- sensitivity. Conclusion High expression of BAG-1 was related to radiation resistance and may be a novel target for cancer therapy.