  We calculate the axial charges of the proton and its resonances in the
framework of the constituent quark model, which is extended to include the
$qqqq\bar{q}$ components. If 20% admixtures of the $qqqq\bar{q}$ components in
the proton are assumed, the theoretical value for the axial charge in our model
is in good agreement with the empirical value, which can not be well reproduced
in the traditional constituent quark model even though the $SU(6) \bigotimes
O(3)$ symmetry breaking or relativistic effect is taken into account. We also
predict an unity axial charge for $N^{*}(1440)$ with 30% $qqqq\bar{q}$
components constrained by the strong and electromagnetic decays.
