Abstract： Objective: The aim of this study was to observe the effect of radiation on micro-vessel density (MVD) and vascular endothelial growth factor (VEGF) expression in an transplanted tumor of human pancreatic cancer in nude mice and to explore the role of radiotherapy on pancreatic cancer angiogenesis. Methods: After vaccinated pancreatic cancer PANC-1 cells, 20 nude mice were randomly divided into radiation group and control group. Radiation group received the radiation (dose of 20 Gy) and were killed 5 days later. The MVD and VEGF expression were determined by immunohistochemistry and then compared with the control group. Results: The number of MVD in the radiation group was significantly lower than that of the control group (8.30 ± 4.55 vs. 13.60 ± 4.28, P < 0.01). The optical density (OD) of VEGF in the radiation group was higher (2.11 ± 0.54 vs. 1.32 ± 0.61, P < 0.05) compared with the control group. Conclusion: The radiotherapy can reduce the number of vessels and increase the VEGF expression of human pancreatic cancer transplanted tumor in nude mice.