Abstract: Objective：To study the effects of human macrophage metalloelastase（HME） on the expression of cyclooxygenase-2（COX-2）and vascular endothelial growth factor（VEGF）in vivo. Methods：24 nude mice receiving subcutaneous injections of human gastric cancer SCG-7901 cells were randomly divided into four groups, which were treated with HME does of 0.2mg/kg, 0.4mg/kg and 0.8mg/kg, meanwhile control group was treated by equivalent normal saline. The tumors were removed after six weeks treatment,the weights and volume of which were evaluated as well as the weight of the mice. The expression of COX-2 and VEGF was detected by immunohistochemical SP method and Western Blot assay. Microvessel density（MVD） was analyzed in CD34-stained vascular endothelial cell. Results：The growth of xenografts were significantly inhibited by each does groups of HME（ P <0.05）.The depressant effect was most powerful in HME 0.8mg/kg does group among intervention groups. HME depressed the expression ofCOX-2, VEGF and MVD obviously in xenografts（ P <0.05）. Conclusion：The antitumor effect of HME in nude mice may attribute to the anti-angiogenesis in dose dependent manner.