Hepatic cellular cancer (HCC) is one of the most common cancers in the world, which is a serious threat to human health and life quality. More than 700 000 people die of HCC each year on average, and its incidence increases in many countries. Chronic hepatitis Bvirus (HBV) infection has been identified as a dominant risk factor for HCC. The pathogenesis of HBV-induced hepatocarcinogenesis is, however, incom-pletely understood. Evidence currently available supports a key role of the HBV X protein (HBx) in the cancer transformation and malignant tumormetastasis. HBx is a multifunctional regulator that may cooperate with the host factors to exert its effects on transcription, signal transduction, cell cycle progression, apoptosis, protein degradation, expression of oncogene and anti-oncogene. This review presents the current knowledge in the molecular pathogenesis of HBx in the induction of HCC.