The invention provides a transmission of a vehicle which can smoothly execute shift-up and shift-down operations. The transmission is provided with change gears, a shift member, a change drum, a change shaft rotationally operated at a predetermined angle by a rider, and a change operation force transmitting mechanism transmitting the rotation of the change shaft to the change drum. The change operation force transmitting mechanism includes a driven body integrally rotating with the change drum and having a concave portion in an inner peripheral surface, a pole holder arranged in an inner side of the driven body and rotationally reciprocating on the basis of a rotational reciprocation of the change shaft, a pole held to the pole holder, and being displaceable around a supporting point between an engaged state in which a leading end is engaged with the concave portion and a non-engaged state in which a leading end is away from the concave portion toward an inner side in a diametrical direction of the pole holder, an energizing means for energizing the pole to the engaged state, and a limiting means for limiting in such a manner that the supporting point of the pole is not displaced with respect to the pole holder.