Objective To observe the effects of Toxoplasma lysate antigen(TLA)on growth inhibition and tumor angiogenesis in mice B16 melanoma.Methods Twenty mice bearing B16 melanoma were established by subcutaneous inoculating with B16 cells and were randomly divided into the treatment group and the control group 0.1 ml TLA was administered once every two days for the treatment group starting on the seventh day after inoculation.and an equivalent volume of sterile saline was administered similarly in the control group.The mice were sacrificed on 21 th day after the tumor cells was injected.The anti-tumor effects of TLA were observed by measuring the size and weight of tumor.The microvessel density(MVD)and expression of vascdar endotheilial growth factor(VEGF)were observed by immunohistochemical method.Results TLA Can markedly inhibit the B16 melamoa growth in mice.The volume and weight of the tumors in the experimental group were significantly decreased compared with the control group(P＜0.05),and the turnout inhibitory rate was 49.6%.The MVD of experimental group and control was(44.4000±4.7888)and(31.9000±2.6012)respectively,and with a significant difference between two groups(P＜0.05).The VEGF in the treatment group were significantly lower than those in the control group(P＜0.05).Conclusion TLA can inhibit the growth of the B16 melanoma in mice.suggesting that the anti-tumor effect induced by TLA via a possible antianigionesis mechanism.