A driving belt and method of assembling the same, which can fit rings with elements easily even at a final phase of fitting work. In a driving belt V two rows of endless rings 8a and 8b are accommodated and held parallel to each other in a recess 7 of a plurality of elements 1 interlinked annularly in a manner to situate the recess 7 to open to an outer circumferential side and in a manner to pivot with respect to the adjoining elements 1, and the element 1 include plural types of elements 1a and 1b having different configurations of the recess 7.