Abstract: Objective: To investigate the effect of radio frequency ablation (RFA) on tumor angiogenesis in liver VX2 tumors and metastases. Methods:The VX2 tumor models were established and divided into three groups randomly: the mice in the control group were sacrificed following the surgery to examine samples of lung and liver tumor; those in the experimental groups were treated with RFA and then sacrificed4h or 24h after the surgical operation to obtain the liver and lung tissues. There were 5 mice in the control group with normal organs. The protein expression of VEGF and microvessel density (MVD) was detected using immunohistochemistry and VEGF-mRNA expression was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Results: VX2 tumor cells showed infiltrative growth. After RFA, large areas of necrosis in the central ablation area were surrounded by an inflammatory reaction zone and peripheral residual tumor was observed. Results of immunohistochemistry indicated that the protein expression of VEGF and MVD were both higher in the control group than in the experimental groups, and the expression levels in residual tumors were obviously decreased. However, lung metastases differ. RT-PCR showed that the gene grey scale of VEGF/GAPDH in lung metastases is1.117 ± 0.1254, and showed no difference after RFA ( 1.0465± 0.1366 and 1.0574± 0.1452 respectively at 4h and 24h, P>0.05). Conclusion:RFA can downregulate MVD and VEGF expression, thus inhibiting angiogenesis. However, RFA has no influence on angiogenesis in distant tumors.