Abstract: Objective To explore the relationship between DNA repair capacity and susceptibility of hepatocellular carcinoma(HCC).Methods Totally 150 newly histopathologically diagnosed HCC patients were enrolled as the case group and 150 non-cancer patients as the control.DNA repair capacity was tested with comet assay.Results Before exposure to bleomycin(BLM) agent,the tail length and moment were 3.98±2.35 and 1.41±0.85 in the HCC group,respectively.Compared with that of peripheral lymphocyte of control group 3.60±2.04,1.24±0.66,there was no difference in the comet tail length and moment between the case and the control group(P>0.05).Fifteen minutes repair after the exposure,the tail length and moment were 6.60±3.11 and 2.59±1.56 in the HCC group.Compared with that of the control(4.69±2.44,1.58±0.96),both the comet tail length and the tail moment in HCC group were significantly higher,indicating severe DNA injury in HCC group(P<0.01).With comet tail length as an indicator,the median of DNA repair capacity in HCC group was 78.65%,lower than 93.81% in the control(P<0.01).And with comet tail moment as an indicator,the median of DNA repair capacity in HCC group was 77.78%,lower than 93.11% in the control(P0.01).Conclusion The low DNA repair capacity may be the risk factor of HCC and DNA repair capacity can function as the warning biomarker of HCC onset.