If a liver cancer with tumor is detected by ultrasound or CT, it is important to identify whether this tumor occurs in the liver or is metastasized from a malignant tumor elsewhere. This is because the treatment methods and therapeutic effects of these two types of liver cancer are significantly different. Liver cancer that occurs from malignant transformation of hepatocytes or tiny bile duct epithelial cells in the liver is called primary liver cancer. If malignant tumors from other organs metastasize to the liver through blood or lymphatic vessels, this type of liver cancer is called secondary liver cancer. Most primary liver cancers have hepatitis and or cirrhosis as the basis, and markers of hepatitis B or C virus infection can often be detected, and fetoprotein can be detected in the serum of most patients. In contrast, most secondary hepatocellular carcinomas do not have a background of liver disease and often have a history of surgery for gastrointestinal, lung, or breast cancer or have primary cancer detected in these organs. Primary hepatocellular carcinoma is better treated by surgery if no intrahepatic or distant metastasis has occurred. As for secondary liver cancer, since it has metastasized from the primary organ to the liver, it is difficult to achieve radical cure with surgical treatment, so non-surgical treatment methods such as chemoembolization therapy are mostly used.