Abstract: Exosomes are important pathways of intercellular communication and have lipid bilayer structure. Neighboring cells or distant cells are capable of exchanging genetic or metabolic information via exosomes binding to recipient cell and releasing bioactive molecules, nucleic acid, protein and other substances to participate in various physiological or pathological activities. Similar to blood exosomes, salivary exosomes contain important biological genetic information, and have significant advantages such as non-invasiveness, easy collection, and high compliance. Salivary exosomes have been proved to be closely related to head and neck diseases and systemic diseases, which is of great significance in clinical detection and diagnosis. However, the research on the mechanism of salivary exosomes and disease occurrence and development is still in the early stage. In this review, we first describe the characteristics of salivary exosomes, and then describe the roles of salivary exosomes as potential biomarkers in oral diseases and other systemic diseases. In view of the great potential of salivary exosomes in disease detection, understanding the mechanism of salivary exosomes provides a new idea for the application of salivary exosomes in clinical detection.