Purpose:To determine the mechanism of danshen, chishao affecting Walker 256 liver metastasis in experimental rat. Methods:Serum VEGF concentrations in experimental rats were detected by ELISA, and the microvascular density (MVD) in tumor tissues were measured by immunohistochemistry staining. Results:The concentrations of serum VEGF in rats were asceding after administered danshen and chishao, MVD in huoxuehuayu group was higher than normal saline group. The incidences of hepatic metastasis, bloody ascites and peritoneal spread in huoxuehuayu group were higher than normal saline group. Conclusions:Danshen, chishao can promote invasion and metastasis of tumor in the experimental rats by enhancing the expression of VEGF and angiogenesis.