乙型肝炎病毒表面抗原 (HBsAg) 定量检测是临床治疗乙型肝炎的一个非常重要的指标，它不仅能区分乙型肝炎病程的各种分期，而且对药物治疗效果及预后有良好的预测作用。本文从乙型肝炎病毒表面抗原的结构、定量检测的方法学以及在临床中的应用等方面做一综述分析。

Quantitative detection of hepatitis B virus surface antigen (HBsAg) is a very important indicator of clinical treatment of hepatitis B virus infection．It can not only distinguish the course of the various stages of hepatitis B, but play a good predictive role in treatment and prognosis. The following aspects of the structure of the hepatitis B virus surface antigen, quantitative detection methodology as well as application in clinical treatment were summarized.