Objective The objective of this study is to investigate the effect of epidermal growth factor receptor （EGFR） monoclonal antibody MAb225 on repair of DNA double strand break（DNA-DSB） after radiation in tongue squamous cell carcinoma cell. Methods The single cell gel electrophoresis（SCGE） was performed to estimate the repair of DNA-DSB induced by radiation in human tongue carcinoma cells Tca8113 treated with or without MAb225. Expression of Ku70 and Ku80 were detected by semiquantitative reverse transcription polymerase chain reaction and Western bolt. Results Comet tail moment of MAb225 treated cell was significantly higher than untreated cell（P
