A two piece type drive (propeller) shaft assembly comprises first and second shafts and a middle elastic member which resiliently connects the first and second shafts end to end so that power can be transmitted. At least one weight is fixed to each shaft at a predetermined unbalance position to shift a principal axis of inertia of the shaft to a desired orientation to suppress whirling motion of the shaft. In each shaft, the at least one weight is located at such a position that the distance of the unbalancing at least one weight from the connected end of the shaft is substantially equal to one third of length of the shaft.
