AIM: To investigate the effects of thalidomide on angiogenesis, tumor growth and metastasis of hepatocellular carcinoma in nude mice. METHODS: Twenty-four nude mice were randomly divided into therapy group and control group, 12 mice in each group. Thalidomide dissolved in 0.5% sodium carboxyl methyl cellulose (CMC) suspension was administered intraperitoneally once a day at the dose of 200 mg/kg in therapy group, and an equivalent volume of 0.5% CMC in control group. Mice were sacrificed on the 30th d, tumor size and weight and metastases in liver and lungs were measured. CD34 and VEGF mRNA in tumor tissue were detected by immunohistochemistry and semi-quantitative RT-PCR respectively and microvessel density (MVD) was counted. Serum concentrations of TNF-α and ALT and AFP were also tested. RESULTS: MVD and VEGF mRNA in therapy group were less than those in control group (31.08±16.23 vessels/HP vs 80.00±26.27 vessels/HP, 0.0538±0.0165 vs 0.7373±0.1297, respectively, P<0.05). No statistical difference was observed in tumor size and weight and metastases in liver and lungs. TNF-α was significantly lower in therapy group than in control group (28.64±4.64 ng/L vs 42.69±6.99 ng/L, P<0.05). No statistical difference in ALT and AFP was observed between groups. CONCLUSION: Thalidomide can significantly inhibit angiogenesis and metastasis of hepatocellular carcinoma. It also has inhibitory effects on circulating TNF-α. AIM: To investigate the effects of thalidomide on angiogenesis, tumor growth and metastasis of hepatocellular carcinoma in nude mice. METHODS: Twenty-four nude mice were randomly divided into therapy group and control group, 12 mice in each group. Thalidomide dissolved in 0.5% Mice were sacrificed on the 30th d, tumor size and weight (CMC) suspension was administered intraperitoneally once a day at the dose of 200 mg / kg in therapy group, and an equivalent volume of 0.5% CMC in control group. and metastases in liver and lungs were measured. CD34 and VEGF mRNA were detected in immunohistochemistry and semi-quantitative RT-PCR respectively and microvessel density (MVD) was counted. Serum concentrations of TNF-α and ALT and AFP were also tested . RESULTS: MVD and VEGF mRNA in therapy group were less than those in control group (31.08 ± 16.23 vessels / HP vs 80.00 ± 26.27 vessels / HP, 0.0538 ± 0.0165 vs 0.7373 ± 0.1297, respectively, P <0.05) tistical difference was observed in tumor size and weight and metastases in liver and lungs. TNF-α was significantly lower in therapy group than in control group (28.64 ± 4.64 ng / L vs. 42.69 ± 6.99 ng / L, P <0.05) Statistical difference in ALT and AFP was observed between groups. CONCLUSION: Thalidomide can significantly inhibit angiogenesis and metastasis of hepatocellular carcinoma. It also has inhibitory effects on circulating TNF-α.