Ferritin is a soluble tissue protein used to store iron in the body. Normal human serum contains a small amount of ferritin, but different detection methods have different normal values. Generally speaking, the normal average value of men is about 80- 130 μ g/L (80- 130 ng/mL), and that of women is 35-55 μ g/L (35-55 ng/mL). In recent years, it has been found that liver cancer also contains an acidic isoferritin called carcinoembryonic isoferritin, which may be helpful for early diagnosis. The reasons for the increase of ferritin in patients with liver cancer may be as follows: ① Liver cancer cells can synthesize and secrete ferritin or isoferritin. ② The uptake and clearance of ferritin in liver cancer tissues were affected. ③ Liver cells are damaged and necrotic, and ferritin stored in the cytoplasm of liver cells overflows into the blood. Although serum ferritin is not specific, except for liver cancer and pancreatic cancer, other digestive tract tumors such as esophageal cancer, gastric cancer and colorectal cancer are not elevated. Serum ferritin in patients with liver cancer who are effective in treatment is decreased, while serum ferritin in patients with deterioration and recurrence is increased. If it continues to increase, it will not be good after treatment. Therefore, the determination of serum ferritin can be used as one of the means to monitor the curative effect, especially for patients with AFP negative.