To investigate the inhibitory effects of Citaowan (CTW) on the growth and angiogenesis of breast cancer in vivo. Orthotopic breast cancer model was established by injection of MDA-MB-231 cells into mammary fat pad of nude mice. Seven weeks after injection, CTW was orally administered at dose of 50, 100 mg/mouse every day for 40 days. Body weight, tumor volume, tumor apoptosis, microvessel density and tumor proliferation were evaluated, after the mice were sacrificed. The body weight and tumor volume were not significantly changed in CTW group compared with the control group. Tumor apoptosis, proliferation and microvessel density were significantly reduced in CTW group (100 mg/mouse) compared with the control group. These data indicate that CTW has anti-angiogenic and proapoptotic effects on breast cancer.