Abstract: Objective To investigate the expression properties of pEgr-Endostatin-EGFP plasmid and the effects of pEgr-Endostatin-EGFPgene-radiotherapy on melanoma tumor-bearing mice. Methods The pEgr-Endostatin-EGFP plasmid was transfected into B16 cell line with liposome. The expression property of Endostatin was investigated by western blot. Tumor-bearing mice were treated by the plasmid injection and then with 5Gy X-irradiation for three times.Tumor growth was observed for 18 days after treatment. The formation and change of tumor capillary were measured with histochemistry assay at the end of the experiment. Results The expression of Endostatin could be detected in B16 melanoma cells which transfected with pEgr-Endostatin-EGFP plasmid, no matter the cells received 2Gy irradiation or not. The C57BL/6J mice, which have been treated with B16 melanoma, pEgr-Endostatin-EGFP recombinant plasmid and local X-irradiation, showed significant difference in the inhibitory effect on the tumor growth (P<0.01) comparing with the control groups..The inhibitory effect of pEgr-Endostatin-EGFP gene-radiotherapy on the tumor growth is correlated with the marked decrease of intratumoral vascularization (P<0.01). Conclusion This work provides a potential antiangiogenic approach in gene-radiotherapy for cancer.