Abstract: Objective To investigate the efficacy of nucleic amplification and microfluidichip assay in the detection of hepatitis C virus(HCV) and judging theinfectivity of HCV in samples around Cutoff Value by ELISA. Methods Total 24 blood samples with Signal-to-Cut-Off Ratios(S/CO) values between 0.4 and 1.0 by anti-HCV ELISA and being negative by colloidal gold were collected and re-tested by using nucleic acid amplification and microfluidic chip assay and HCV CLIA. Results Among the 24 samples,16 were positive(66.67%) by nucleic acid amplification and microarray,16 were positive(66.67%) by CLIA,6 were positive(25.00%) by ELASA reagent①,and 10 were positive(41.67%) by ELISA reagent②.Nucleic acid amplification and microarray analysis were compared with the results of ELISA reagent① or reagent②,the difference in the positive rate was significant(P<0.01 and P<0.05,respectively). Conclusion Nucleicacid amplification and microfluidic chip analysis method on the detection rate of HCV is higher than that of ELISA method and colloidal gold method,therefore,the blood samples around Cutoff Value by anti-HCV ELISA assay might be with infectivity of HCV,and these samples could be tested by nucleic amplification and microfluidic chip assay or CLIA,in order to improve the detection results and prevent false detections.