Objective To assess the clinic application of a new-style automated immunoassay system HISCL ( high sensitivity chemiluminescent enzyme immunoassay ) with high sensitive chemiluminescence substrate CDP-Star?, bind-free separate technology and filter conversion technology.Methods The performance verification test evaluated HISCL′s specification including reproducibility, functional sensitivity, linearity, accuracy, and sensitivity for HBsAg seroconversion.To evaluate the specificity , 1 007 HBsAg-negative specimens , 82 potentially interfering specimens were from conventional specimens in West China Hospital , Sichuan University between October and December of 2014.At the same time, with these results to determine the rate of the specimens that their results are in negative grey zone.259 HBsAg-positive specimens and 27 weakly-positive specimens were tested for the comparison between the HISCL and ECLIA ( electrochemiluminescence immunoassay ) HBsAg quantification.A linear regression model , Pearson′s correlation and Bland-Altman analysis were used as statistical methods.Results The between day and within-lot variable coefficient of two level samples are 1.55%, 2.02%, 0.34%, 1.34%separately.The functional sensitivity of the HISCL HBsAg assay reaches 0.007 IU /ml.There is a good linearity (y=3.262x+0.082,r=0.994; y=2 303.608x-33.006,r=0.999) within range of 0-2 300 IU/ml.HISCL obtain the accurate results for the CAP control material , the agreement rate is 100%.The sensitivity for the detection of HBsAg seroconversion is high.The specificity is 99.91%.The negative grey zone rate is 1.66%.The results of these two methods have good correlation and uniformity , r=0.995, LOA:-0.3 -0.19 log10 IU/ml.Conclusions HISCL HBsAg detection system shows good detection performance.Be of the function of both qualitative and quantitative detection.And the negative “grey zone”specimen rate is low.It is wholly capable of wide linearity and quick assays for quantifying serum HBsAg levels.HISCL could contribute to improve HBsAg quantitative detection process for clinical laboratory.