1. Pathological diagnostic criteria: biopsy or surgical excision of tissue specimens from occupied liver lesions or extrahepatic metastases, diagnosed as HCC by pathological histological and/or cytological examination, is the gold standard. 2. Clinical diagnostic criteria: Among all solid tumors, only HCC can be diagnosed using clinical diagnostic criteria, which are recognized both domestically and externally and are generally considered to depend on three major factors, namely, the background of chronic liver disease, imaging findings and serum AFP level; it is required that HCC can be established when both (1) + (2) a or (1) + (2) b + (3) three of the following conditions are met Clinical diagnosis: (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 hepatic occupancy in the arterial phase with rapid heterogeneous vascularity (Arterial hypervascularity), and Venous or delayed phase washout. (1) HCC can be diagnosed if the diameter of liver occupancy is ≥50px and one of the two imaging examinations of CT and MRI shows that the liver occupancy has the characteristics of hepatocellular carcinoma mentioned above; (2) If the diameter of liver occupancy is 1-50px, both imaging examinations of CT and MRI are needed to show that the liver occupancy has the characteristics of hepatocellular carcinoma mentioned above in order to strengthen 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.