Abstract: Objective: To observe the effect of inhibition of vascular endothelial growth Factor (VEGF) antibody on the growth of human osteosarcoma. Methods: A 100μg intratumoral injection of VEGF monoclonal antibody around tumor and neoplasm of nude tumor-bearing mouse was administered on alternate day in treatment group and the injection of PBS of same amount was done in the controls. The administration totals 6. The gross volume and humid weight of tumor were measured, the microvessel density (MVD) of tumorous tissues was observed using immunohistochemistry and pathological examination was conducted with light microscope. Results: There was a significant difference in gross volume, weight and MVD value of the tumor between the treatment and control group. The inhibition rate of treatment group reached 54.05% and there was a significantly lower MVD in treatment group than in the controls. Pathological results showed that there were some sporadic punctiform or linear necrotic foci in the treatment group but few were found in the controls. Conclusion: Anti-VEGF monoclonal antibody can effectively inhibit the angiogenesis of transplantation tumor of osteosarcoma in nude mouse.