The phase-matching angle and pump energy dependence of transverse beam profiles on traveling-wave parametric generation in KTiOPO4 crystals are numerically calculated and compared with the previously measured results. It is found that the idler beam profile stretches in its walk-off direction and the signal beam profile stretches in the opposite direction as the idler walk-off angle becomes large due to the walk-off and back-conversion effects in the propagation process. It is also found that, even if walk-off does not exist, the transverse beam profile has a manifold ring shape as the pump energy is increased due to repeated conversion and back-conversion.