  We point out the possibility to detect the low-energy signals of moduli in
the superstring theory through the neutrino oscillation. The idea is based on
the characteristics that the couplings of moduli are different from matter to
matter. We estimate the oscillation probability both in the baseline and solar
neutrino oscillations. In both cases, when there is at least one modulus of
which mass is less than or equal to $10^{-19}$ GeV, the interaction of the
modulus significantly changes the conversion probability from one neutrino
flavor to another.
