  Angular-dependent in-plane magnetoresistance (AMR) for single crystal
$Na_{0.34}(H_3O)_{0.15}CoO_2$ with charge ordering is studied systematically.
The anisotropic magnetoresistance shows a twofold symmetry at high temperature
with rotating H in the Co-O plane, while a sixfold symmetry below a certain
temperature ($T_\rho$). At $T_\rho$, the symmetry of AMR changes from twofold
to fourfold with rotating magnetic field (H) in the plane consisting of the
current and c-axis. The variation of AMR symmetry with temperature arises from
the subtle changes of the spin structure. These results give a direct evidence
for the itinerant electrons directly coupled to the localized spins.
