Hepatitis C virus( HCV) is one of the major causes of acute and chronic hepatitis,liver cirrhosis,and hepatocellular carcinoma.Laboratory diagnosis is essential for the diagnosis of HCV infection. Laboratory etiological diagnosis of chronic HCV infection includes HCV antigen and antibody detection and quantitative detection of HCV RNA. Quantitative detection of serum HCV RNA is the only laboratory diagnosis index for current HCV infection and plays a very important role in determination of treatment time,selection of treatment regimens,and evaluation of therapeutic effect of antiviral treatment. This paper elaborates on the target population,detection methods,and clinical significance in laboratory screening for chronic HCV infection,so as to provide timely diagnosis and effective treatment of chronic HCV infection.