Diagnostic criteria of hepatocellular carcinoma 1. Pathological diagnostic criteria: biopsy or surgical excision of tissue specimens of hepatic occupying lesions or extrahepatic metastases, diagnosed as HCC by pathological histological and/or cytological examination, which is the gold standard. 2. Clinical diagnostic criteria: Among all solid tumors, only HCC can be diagnosed using clinical diagnostic criteria, which are recognized domestically and externally as non-invasive, simple, convenient and highly operable, and are generally considered to depend mainly on three major factors, namely chronic liver disease background, imaging findings and serum AFP level; however, the understanding and specific requirements of the academic community vary and often change, and there are errors in practical application. Therefore, taking into account China’s national situation, previous domestic standards and clinical practice, the expert group proposed that a strict grasp and joint analysis is appropriate, requiring that the clinical diagnosis of HCC can be established when both (1)+(2)a or (1)+(2)b+(3) of the following conditions are met: (1) evidence of cirrhosis and HBV and/or HCV infection (HBV and/or HCV antigen-positive) (2) typical imaging features of HCC: simultaneous multi-row CT scan and/or dynamic contrast-enhanced MRI showing rapid heterogeneous vascularity in the arterial phase and rapid washout in the venous or delayed phase. (1) If the diameter of liver occupancy is ≥2 cm, one of the two imaging examinations of CT and MRI shows that the liver occupancy has the characteristics of hepatocellular carcinoma mentioned above, HCC can be diagnosed; (2) If the diameter of liver occupancy is 1-2 cm, both imaging examinations of CT and MRI need to show that the liver occupancy has the characteristics of hepatocellular carcinoma mentioned above before HCC can be diagnosed to enhance the specificity of diagnosis. (3) Serum AFP ≥ 400 μg/L for 1 month or ≥ 200 μg/L for 2 months, and other causes of elevated AFP can be excluded, including pregnancy, germline embryonic-derived tumors, active liver disease and secondary liver cancer.