Hepatocellular carcinoma is a cancer that occurs in hepatocytes or intrahepatic bile duct cells. Currently, the etiology and pathogenesis of hepatocellular carcinoma have not been fully elucidated and may be related to a combination of factors. Although hepatitis virus, aflatoxin B, and other chemical carcinogens are importantly related to the development of liver cancer, patients with liver cancer do not have pathogens (bacteria, viruses, fungi, parasites, etc.) discharged, therefore, liver cancer is not contagious. The risk of liver cancer for those who have close contact with liver cancer patients is not greater than that for those who do not have contact with liver cancer patients. Therefore, there is no need to take isolation measures for liver cancer patients, and people who have contacted or cared for liver cancer patients do not need to worry about being infected with liver cancer. It should be noted that liver cancer patients in China, unlike those in Europe and the United States, mostly develop liver cancer on the basis of viral hepatitis. If liver cancer is accompanied by active hepatitis, then it is contagious. However, what can be contagious is the hepatitis virus in the body of liver cancer patients, not liver cancer, and liver cancer itself is not directly contagious, but the family gathering of liver cancer patients is caused by living habits plus diseases that may be transmitted to each other. If a family has a history of hepatitis B or liver cirrhosis, the chance of liver cancer is high. And with the high mortality rate of late stage liver cancer, it is not surprising that a family dies from liver cancer one after another. Since hepatitis B can be transmitted to each other through close contact, hepatitis B vaccination can prevent hepatitis B and thus interrupt the trilogy of “chronic hepatitis – cirrhosis – liver cancer”. “However, it should not be mistaken that liver cancer is contagious.