objective;To study the effect of Runing Ⅱ(a Chinese herbal preparation for mammary cancer)on the growth and metastasis of transplanted tumor of mammary cancer MA-891-bearing TA2 mice and its mechanism.Methods;The model of mammary cancer MA.891 cell strain transplanted tumor of TA2 mice with lung metastasis were developed to observe the effect of Runing Ⅱon the growth and metastasis of the transplanted tumor.The immunohistochemical method and image analysis were adopted to detect the levels of vascular endothelial growth factor(VEGF),vascular endothelial growth factor receptor(VEGFR),and micro-vessel count(MVC)and micro-vessel area(MVA).Results;In the Runing Ⅱgroup,the tumor weight inhibition rate and the lung metastasis inhibition rate were 37.3%and 65.4%respectively,the tumor growth and lung metastasis were obviously inhibited;And the levels of VEGF and VEGFR,MVC and MVA were significantly decreased as compared with those in the tumor-bearing control group(P＜0.05).Conclusion;The Chinese herbal preparation Running Ⅱcan inhibit the metastasis of tumor through inhibiting the angiogenesis,and the mechanism is possibly related with down-regulation of VEGF and VEGFR expression.