Olfactory receptors (OR) are not only expressed in the olfactory sensory neurons, but also widely expressed in all other human tissues tested to date, and playing important physiological roles. In this review, the existing data concerning the expression of olfactory receptors, as well as the functions in non-olfactory tissues and cells. The functions of these ORs are primarily to maintain normal physiological functions by controlling the endogenous chemicals surrounding the cells, and to represent specific functions when stimulated by selected exogenous ligands. In the field of medicine, about 40% of listed drugs are targeted at the G protein coupled receptors (GPCRs) family, and ORs are the largest member of GPCR subfamily. We speculate that these olfactory receptors may become important drug targets in the future. This review of OR functions, on the one hand, is beneficial to use OR as a potential drug target to develop new drugs; on the other hand, it also provides a new research idea for the pharmacological action of volatile monomers in traditional Chinese medicine.