Abstract: Early diagnosis of hepatocellular carcinoma (HCC)is the key point for clinic healing, and accurate staging is the foundation of rational therapy. Positron emission tomography with ¹⁸F-fluorodeoxyglucose(¹⁸F-FDG) PET isn't sufficiently sensitive on detecting HCC, hut the positive imaging is related on many factors such as malignant degree, intra/extrahepatic metastases, tumor thromhus in a portal vein, the level of alpha-fetoprotein in blood serum and so on. Thus, ¹⁸F-FDG PET has a special value on moderately or poorly differentiated HCC for differential diagnosing, staging and restaging, monitoring responses to treatments, evaluating therapeutic effects, and predicting the prognosis.