Objective To explore the radiosensitization effect of thalidomide combined with X-ray on esophageal carcinoma TE1 cells.Methods Cell scratch assay Was used to detect the inhibition ability of different concentration of Thalidomide on cell invasion and metastasis.H3-TdR incorporation assay Was used to investigate the inhibition of DNA synthesis in TE1 cells by treated with Thalidomide singly or combination with X-rays.The colony formation assay Was used to analyze the radiosensitization of Thalidomide effect on TE1 cells.Results Thalidomide had obvious inhibition effect on TE1 cell metastasis.DNA synthesis and colony formation,which were correlated with drug concentration.The values D0,Dq and SF2 in TE1 cells were gradually decreased with thalidomide concentration increased.When the concentration of thalidomide was 100μg/ml,the SERD0 and SERDq were(1.4±0.2)and(1.5±0.1),respectively,While the concentration of thalidomide Was 1 50μg/ml,the SERD0 and SERDq were metastasis,DNA synthesis,and significantly enhance the radiosensitizing effect on esophageal carcinoma TE1 cells.