We have studied the photon echo in ultrafast modulation spectroscopy in a cascade three-level system (UMSCTS).When the pump beams have broadband linewidth,the one-photon and two-photon four-wave mixings are related to the three-pulse stimulated photon echo and sum-frenquency three-level echo when τ＞0,respectively;while the result should coincide with the case that the beams have narrow linewidth when τ＜0.