A single alpha-fetoprotein cannot be used to confirm the diagnosis of liver cancer, and greater than 400μg/L or higher than 200ug/L for two months have certain indications. Hepatocellular carcinoma is a common malignant tumor of the liver, mainly including hepatocellular carcinoma and cholangiocellular carcinoma, and the growth of the tumor is accompanied by the elevation of some substances, which are called tumor markers. However, the diagnosis needs to be combined with imaging examination or pathological biopsy for comprehensive judgment, and the diagnostic criteria are as follows: 1. The gold standard of liver cancer diagnosis is positive liver puncture biopsy. 2. Positive results of two imaging tests suggest liver cancer, and the characteristic imaging manifestations of liver cancer include CT-enhanced fast-in-fast-out sign. 3. One imaging test suggests hepatocellular carcinoma, and the persistence of alpha-fetoprotein greater than 400μg/L can also confirm the diagnosis of hepatocellular carcinoma. In addition, for liver malignant tumors such as cholangiocarcinoma and metastatic hepatocellular carcinoma, the diagnostic value of alpha-fetoprotein is lower. For the definite diagnosis of liver cancer, it is necessary to improve relevant examinations, and cannot rely on one single alpha-fetoprotein alone to confirm the diagnosis. Elevated alpha-fetoprotein may also be due to other primary diseases, so it is necessary to consult doctors and improve relevant examinations in time to avoid deterioration of the situation.