Abstract: Objective 　To assess the effect s of thalidomide on VEGF-C and KDR expression in human breast cancer cell lines, MCF-7 and MDA-MB-231. Methods 　Breast cancer cells were treated with thalidomide, then cell proliferation were examined by the method of MTT. The level of VEGF-C mRNA expression was distinguished by semi-quantitative RT-PCR technique. Flow cytometry was applied to examine the protein expression of VEGF-C and KDR. Results 　Within the concent ration of (60～120) μg/ml, thalidomide strongly inhibited proliferation of MCF27 and MDA-MB-231. When the drug is 60 μg/ml, thalidomide can inhibit the mRNA expression of VEGF-C and the protein expression of VEGF-C and KDR. Conclusion 　Within a certain drug concent ration, thalidomide can inhibit human breast cancer cell proliferation. Its role of inhibiting angiogenesis maybe relate with down regulating the expression of VEGF-C and KDR.