An electric massage bed includes a bed frame having a plurality of support brackets, a plurality of mattress sets each having a retaining plate mounted on one of the support brackets of the bed frame and a mattress supported by the retaining plate, and a vibrating motor mounted on a bottom side of the retaining plate of one of the mattress sets. When the vibration generated from the vibrating motor is transmitted to the associated mattress of the mattress set that is equipped with the vibrating motor, the unexpected vibration wont occur in the other mattress sets because the mattress sets are spaced from each other, thereby enhancing the comfort of a user lying down on the mattresses.
