The accuracy of alpha-fetoprotein test for liver cancer is relatively high, and about 60% to 70% of primary liver cancer patients will have elevated levels of alpha-fetoprotein. However, alpha-fetoprotein test is not only for liver cancer patients, serum alpha-fetoprotein level of acute and chronic hepatitis, cirrhosis, gastric cancer, etc. will also be elevated to different degrees. Alpha-fetoprotein is a kind of glycoprotein, which is closely related to the occurrence of liver cancer and other systemic tumors. At present, it is mainly used for the diagnosis of primary liver cancer and efficacy monitoring in clinic, and about 60% to 70% of primary liver cancer patients have increased levels of alpha-fetoprotein, and the levels of alpha-fetoprotein of other systemic malignant tumors, such as ovarian, gastric, and intestinal cancers, are also elevated. In benign liver diseases, the level of alpha-fetoprotein is also elevated, mostly transiently, while in liver cancer, the level of alpha-fetoprotein is persistently elevated. Dynamic observation of alpha-fetoprotein level can be used for early diagnosis of liver cancer and for recurrence monitoring after liver cancer surgery.