Abstract: Hepatocellular carcinoma（HCC）is one of the most common tumors worldwide， with a high percentage of mortality as well as extremely poor prognosis. The occurrence of HCC involves a variety of mutations in oncogenes or tumor suppressor genes. However， its specific molecular mechanism is unclear. Exosome is one kind of the extravascular vesicles， which can mediate substance exchange and information communication. Recent studies demonstrate that exosomes contribute to occurrence and development of HCC. Moreover， exosomes can be utilized into the diagnosis and therapy of HCC. This article summarizes the contents and function of exosomes， their effects on occurrence and development， diagnosis and therapy of HCC as well.