Organs do not independently coordinate their metabolic activity:close communication between different organ systems is essential to regulate metabolism effectively. In recent years, the unfolded protein response(UPR), which is an adaptive mechanism to decrease the amount of unfolded or misfolded proteins in the ER, has been found to regulate metabolic function not only at the cellular level but also at the whole-organism level by way of inter-organ communications. This manuscript will present the most recent findings on the role of the UPR in inter-organ metabolic networks.