The most important cause of liver cancer may be the hepatitis virus. The relationship between different types of hepatitis viruses and hepatocellular carcinoma varies. (1) Hepatitis A virus (HAV): this type of hepatitis has better regression and prognosis, and sclerosis and hepatocellular carcinoma rarely occur. Zhang Song, Department of Oncology Radiotherapy, Zhengzhou People’s Hospital (2) Hepatitis B virus (HBV): about 1/3 of primary liver cancer patients have a history of chronic hepatitis and the presence of HBsAg in liver cancer cells; HBV-DNA exists in liver cancer cells. A. The geographical distribution of HBV and liver cancer is basically the same, and epidemiological studies in many countries and regions show that the rate of HBV infection is also higher in areas with high incidence of liver cancer. B. The rate of HBV positivity in the serum of liver cancer patients is increased. C. HBV infection is aggregated in liver cancer family lines. D. The incidence of hepatocellular carcinoma is significantly higher in HBV carriers. E. HBV markers such as HBsAg and HBV-DNA were significantly increased in liver cancer and liver tissues around the cancer. All the above data indicate that HBV is closely related to the occurrence of liver cancer and is a major factor in the etiology of liver cancer. (3) Hepatitis C virus (HCV): the rate of HCV positivity among liver cancer patients in China is 7.5%-42.9%, and currently HCV infection is not the main cause of liver cancer in China. In conclusion, according to existing studies, hepatitis virus (mainly referring to hepatitis B and C viruses) is the main cause of liver cancer and has a close relationship with the development of liver cancer.