Hepatocellular carcinoma, i.e. malignant tumor of the liver, can be divided into two categories: primary and secondary. Primary liver malignancies originate from the epithelial or mesenchymal tissues of the liver. The former is called primary liver cancer, which is a highly prevalent and dangerous malignancy in China; the latter is called sarcoma, which is less common compared with primary liver cancer. Secondary or metastatic hepatocellular carcinoma refers to the invasion of malignant tumors from multiple organs of the body to the liver. It is usually seen as liver metastasis from malignant tumors of stomach, biliary tract, pancreas, colorectum, ovary, uterus, lung, breast and other organs. (A) Pathological diagnosis 1. Histological examination of liver confirms primary hepatocellular carcinoma. 2. Histological examination of extrahepatic tissues confirms hepatocellular carcinoma. (B) Clinical diagnosis 1. If there is no other evidence of hepatocellular carcinoma with positive AFP convection method or AFP>400mg/ml for more than four weeks by radioimmunoassay and can exclude active liver disease of pregnancy germinal gland embryogenic tumor and metastatic hepatocellular carcinoma 2.B-type ultrasound imaging can show tumor with diameter over 2cm, which is of great value for early localization; electronic computerized X-ray tomography (CT) can show tumor with diameter over 1,0cm; radionuclide scan can show tumor with diameter over 3-5cm; other X-ray hepatic angiography and nuclear magnetic resonance imaging have certain value for diagnosis of liver cancer. 3. Imaging examination with clear intrahepatic substantial occupying lesions can exclude hepatic hemangioma and metastatic liver cancer and has one of the following conditions: ① AFP>20mg/ml. ② Typical imaging manifestation of primary liver cancer. ③No jaundice but significantly increased AKP or r-GT. ④Distantly defined metastatic lesions or bloody ascites or cancer cells found in ascites. ⑤ Clearly positive hepatitis B markers for cirrhosis.