In recent years, with the increase of liver cancer patients, the occurrence of liver cancer has gradually aroused people’s concern, and liver cancer in China is mainly caused by the following factors. I. Chronic viral hepatitis is one of the most common causes of liver cancer. There are mainly two kinds of chronic hepatitis B and chronic hepatitis C that pose the greatest threat. Especially, the incidence of primary liver cancer in hepatitis B and hepatitis B virus carriers is 2-100 times higher than that of normal people. According to the data, about 80% of liver cancer patients can be found to be positive for e antigen, e antibody and core antibody of hepatitis B. It can be seen that liver cancer and hepatitis B and C are closely related. Aflatoxin B in moldy substances is the most carcinogenic substance in life. Moldy food, rice, corn, feed, etc., all contain this carcinogenic substance, and long-term consumption of food containing this toxin can induce liver cancer. We often see that some family members of liver cancer patients will have liver cancer patients again, which may be related to genetic factors, but common eating habits are also an important reason. Chemical carcinogens are also common cancer-causing factors. Chemical substances that can cause liver cancer are mainly N-nitroso compounds, such as nitrosamines and nitrosamides. In addition, pesticides, alcohol, safrole, etc. can also induce liver cancer. Therefore, we advocate the consumption of green fruits and vegetables in our life. Low immunity is also a cause of liver cancer. We found that people who often stay up late, drink alcohol and overexert themselves have a higher chance of liver cancer than those who live a regular life. This may be related to the decreased immune function caused by the above mentioned reasons, which cannot kill the mutated cells, necrotic cells and senile cells in the body, resulting in an increased incidence of liver cancer. It is believed that plasma of liver cancer patients contains a confinement factor that suppresses cellular immunity and protects liver cancer cells from being killed by immune cells. Methemoglobin has been shown to inhibit the phagocytosis of lymphocytes and macrophages. There are many causes of liver cancer, such as genetic factors, genetic mutation, water pollution, etc., which may cause the occurrence of liver cancer. Therefore, people should pay more attention to it in their daily life.