Hepatitis B virus infection can cause acute hepatitis, chronic hepatitis or latent infection. This is mainly related to the age at the time of infection (different immune status at different ages), usually 90% and 25%-30% of those infected with HBV in perinatal period and infancy will develop chronic infection respectively; only 5%-10% of those infected with HBV in adolescence and adulthood will develop chronic HBV infection. Only 5-10% of adolescents and adults infected with HBV develop chronic HBV infection. More than 90% of adults infected with HBV can be completely cured. This is also one of the reasons why we often find some people positive for anti-HBs and anti-HBc in the five items of hepatitis B in physical examination. The natural course of chronic hepatitis B virus infection is long and can last 30 to 50 years. The period can be divided into an immune tolerance period, an immune clearance period, an immune clearance period, and an inactive or low (non)replication period. Immune tolerance period: characterized by active HBV replication, high HBV DNA titer (>105 copies/ml), positive serum HBsAg and HBeAg, normal level of serum alanine aminotransferase (ALT), and no obvious abnormality in liver histology, which is what we often see in chronic HBV carriers; immune clearance period: manifested by continuous or intermittent increase in serum ALT and aspartate aminotransferase (AST). AST) continuously or intermittently elevated, liver histology with necroinflammation and other manifestations, HBV DNA titer >105 copies / ml, but generally lower than the immune tolerance period, which is usually referred to as chronic hepatitis. Inactive or low (non) replication stage: the manifestations are normal ALT/AST level, no obvious inflammation in liver histology; HBV DNA is undetectable (PCR method) or below the lower limit of detection, HBeAg negative, anti-HBe positive, and this part of the patients become inactive HBsAg carrier state. In patients with chronic hepatitis B, the annual incidence of decompensated cirrhosis is about 3%, and the 5-year cumulative incidence is about 16%. The 5-year mortality rates of chronic hepatitis B, compensated and decompensated cirrhosis are 0%-2%, 14%-20% and 70%-86%, respectively. The 5-year incidence of hepatocellular carcinoma in cirrhotic patients is 6-15%. About 25% of those infected before the age of 6 will develop cirrhosis and primary liver cancer in adulthood. Therefore, there are three general scenarios for the eventual regression of chronic HBV infected patients: lifelong carriage of the virus without disease; or chronic hepatitis B; or further development of cirrhosis and liver cancer. Because chronic infection is often hidden, it is not easy to be detected; even if there are some discomforts such as lack of desire to eat, poor mental health, fatigue or nausea, etc., they will not be noticed. Often, the patient comes to the doctor only when the condition is serious, and many treatment opportunities may have been lost by then. Therefore, we emphasize the need for regular checkups after HBV infection is detected.