  We show the first lattice QCD results on the axial charges $g_A^{N^*N^*}$ of
$N^*(1535)$ and $N^*(1650)$. The measurements are performed with two flavors of
dynamical quarks employing the renormalization-group improved gauge action at
$\beta$=1.95 and the mean-field improved clover quark action with the hopping
parameters, $\kappa$=0.1375, 0.1390 and 0.1400. We construct 2$\times$2
correlation matrices and diagonalize them so that the signals of $N^*(1535)$
and $N^*(1650)$ are properly separated. Wraparound contributions in the
correlator, which can be another source of signal contaminations, are
eliminated by imposing the Dirichlet boundary condition in the temporal
direction. The axial charge of $N^*(1535)$ is found to take small values as
$g_A^{N^*N^*}\sim {\mathcal O}(0.1)$, whereas that of $N^*(1650)$ is
approximately 0.5, which is almost independent of quark masses and consistent
with the predictions by the naive nonrelativistic quark model.
