  We investigate tunneling of excitations across a potential barrier separating
two spin-1 Bose-Einstein condensates. Using the mean-field theory at the
absolute zero temperature, we determine transmission coefficients of
excitations in the saturated magnetization state and unsaturated magnetization
states. All excitations except the quadrupolar spin mode in the saturated
magnetization state show the anomalous tunneling phenomenon characterized as
perfect tunneling in the low momentum limit through a potential barrier. The
quadrupolar spin mode in the saturated magnetization state, whose spectrum is
massive, shows total reflection. We discuss properties common between
excitations showing the anomalous tunneling phenomenon. Excitations showing
perfect tunneling have gapless spectrum in the absence of the magnetic field,
and their wave functions in the low energy limit are the same as the condensate
wave function.
