  Cosmological origins of the two heaviest odd-odd nuclei, $^{138}$La and
$^{180}$Ta, are believed to be closely related to the neutrino-process. We
investigate in detail neutrino-induced reactions on the nuclei. Charged current
(CC) reactions, $^{138}$Ba$ (\nu_e, e^{-}) ^{138}$La and $^{180}$Hf$ (\nu_e,
e^{-}) ^{180}$Ta, are calculated by the standard Quasi-particle Random Phase
Approximation (QRPA) with neutron-proton pairing as well as neutron-neutron,
proton-proton pairing correlations. For neutral current (NC) reactions,
$^{139}$La$ (\nu \nu^{'}) ^{139}${La}$^*$ and $^{181}$Ta$ (\nu, \nu^{'})
^{181}$Ta$^*$, we generate ground and excited states of odd-even target nuclei,
$^{139}$La and $^{181}$Ta, by operating one quasi-particle to even-even nuclei,
$^{138}$Ba and $^{180}$Hf, which are assumed as the BCS ground state. Numerical
results for CC reactions are shown to be consistent with recent semi-empirical
data deduced from the Gamow-Teller strength distributions measured in the
($^{3}$He, t) reaction. Results for NC reactions are estimated to be smaller by
a factor about 4 $\sim$ 5 rather than those by CC reactions. Finally, cross
sections weighted by the incident neutrino flux in the core collapsing
supernova are presented for further applications to the network calculations
for relevant nuclear abundances.
