Liver cancer is one of the most common malignant tumors in China. The causes are diverse and are the result of a combination of factors, and there is no clear and unique cause. The common causes of liver cancer include: Viral hepatitis: it is the most common cause of liver cancer in China, especially hepatitis B infection. Hepatitis B virus will reintegrate hepatocyte DNA and cause oncogene activation and oncogene inactivation. The mechanism of hepatitis C carcinogenesis is related to sequence variation. Patients with viral hepatitis are prone to accumulate genetic mutations leading to cancer due to chronic inflammation, repeated hepatocyte wordsis and regeneration. Aflatoxin: Aflatoxin is a toxin produced by molds and is one of the common carcinogenic factors. Aflatoxin can lead to cancer by affecting gene expression, so areas with severe aflatoxin contamination are often also high incidence areas for liver cancer. Cirrhosis cancer: Some patients with cirrhosis will develop cancer, which is also an important factor in the occurrence of liver cancer, especially cirrhosis caused by hepatitis B is the most common. Other high-risk factors: such as schistosome infection and harmful substances in the environment are all factors leading to cancer, among which parasites are also contagious to a certain extent. Therefore, there are many factors leading to the occurrence of liver cancer, and liver cancer is also the result of many factors acting together, and it can only be said that there are relatively dangerous cancer-causing factors, but there is no absolutely clear sole cause.