  We formulate the chiral perturbation theory at the one loop level in the
effective lagrangian including the $\rho$ meson as a dynamical gauge boson of a
hidden local symmetry(HLS). The size of radiative correction to the
phenomenological parameter $a$ of HLS is estimated to be about $10$\%. The
complete list of ${\cal O}(E^4)$ terms is given and the one loop counter terms
are determined explicitly in the $N$ flavor model. We also obtain matching
conditions to the conventional chiral perturbation of Gasser and Leutwyler in
the chiral limit in a renormalization scale independent manner. We find that
Gasser--Leutwyler's estimates for $L_{9,10}$ are saturated by $\rho$ and its
one loop contributions without introducing non-minimal couplings of
$\pi$-$\rho$ system, suggesting the absence of the tree level $a_1$ meson
contributions.
