  Differential resistance spectra (${\rm d}V/{\rm d}I-V$ characteristics) have
been measured for point-contacts between the heavy-fermion superconductor (HFS)
CePt$_{3}$Si and a normal metal. Some contacts show a peak at V=0 that is
characteristic of HFS coexisting with a magnetic order such as UPd$_2$Al$_3$,
UNi$_2$Al$_3$ and URu$_2$Si$_2$. The evolution of the peak occurs well above
the antiferromagnetic transition temperature $T_{{\rm N}}\sim$ 2.2 K, so that
the direct relationship with the magnetic transition is questionable. The
half-width of the peak seems to reflect the crystal field splitting or the
spin-wave gap as observed for the above-mentioned HFSs, possibly suggesting
that some common scattering process induces the zero-bias peaks in these
materials.
