Objective To establish a quant. detection method for Hepatitis B virus surface antigen (HBsAg) and evaluate its performance.Methods According to the principle of double antibody sandwich, anti-HBsAg polyclonal antibody was linked with acridinium ester, and the other two strains of anti-HBsAg monoclonal antibody were linked with biotin, and magnetic beads were coated by streptavidin.The detection was carried out via streptavidin-biotin separation system and washing process.Results The limit of the detection was 0.05 IU/mL, and the linear range was 0.05-150 IU/mL, also the intra-batch and total variation was lower than 5% and 8%, resp.No HOOK effect was observed in strong pos. samples with a concentration of 106 IU/mL.The relative sensitivity coefficients of the 5 seroconvertion panel, compared with Abbott Architect, Siemens Centaur and Johnson VITROS chemiluminescent reagents, were 3, 0 and -3, resp.National reference plate detection results conform to the requirements.Compared with Abbott Architect HBsAg kit, the sensitivity and specificity of the 2000 clin. samples were 99.77%, 100%, resp., and the consistency was 99.95%.Conclusion The HBsAg quant. test reagent established in this study meets the requirements of the clin. application, with high sensitivity and specificity, and is suitable for clin. application.