Serum alpha-fetoprotein test is mainly used to diagnose liver cancer. The incidence of liver cancer is increasing, and early diagnosis of liver cancer includes not only blood tests for serum alpha-fetoprotein, but also imaging tests, that is, ultrasound of the liver or CT of the liver. When serum alpha-fetoprotein is obviously elevated, the occurrence of liver cancer should be highly emphasized. Liver cancer often occurs in people who have a family history of liver cancer, who drink a lot of alcohol over a long period of time, or who have a history of chronic hepatitis B. Chronic hepatitis B has the trilogy phenomenon of chronic hepatitis B, cirrhosis, and liver cancer. Serum alpha-fetoprotein testing can also be used to diagnose chronic hepatitis or cirrhosis.