Objective: To investigate the effects of circulating exosomes derived from oral cancer patients on the proliferation, migration and invasion of tongue cancer CAL27 cells. Methods: Circulating exosomes were isolated from the peripheral blood of 20 oral cancer patients using gradient centrifugation. The characteristics of the exosome was studied by transmission electron microscope (TEM) and Western blot. After treatment with circulating exosomes, CAL27 cell proliferation was evaluated with MTT assay, migration was observed by cell wound scratch assay and the invasion of CAL27 cells was tested by Transwell assay. CAL27 cell bearing nude mice were used to estimate the effect of circulating exosome on CAL27 cell proliferation and metastasis in vivo. Results: The proliferation, migration and invasion of CAL27 cells were enhanced by circulating exosomes from oral cancer patients. In vivo study showed that the tumorigenesis and metastasis of CAL27 cells were enhanced by circulating exosomes. Conclusion: Circulating exosomes from oral cancer patients can promote the proliferation, migration, invasion and metastasis of CAL27 cells.