  We present the full ${\cal O}(\alpha_{{ew}})$ electroweak radiative
corrections to the Higgs-boson production in association with $Z^0$-boson pair
at an electron-positron linear collider(LC) in the standard model. We analyze
the dependence of the full one-loop corrections on the Higgs-boson mass $m_{H}$
and colliding energy $\sqrt{s}$. We find that the corrections significantly
suppress the Born cross section, and the ${\cal O}(\alpha_{{ew}})$ electroweak
radiative corrections are generally between 1.0% and -15% in our chosen
parameter space, which should be taken into consideration in the future precise
experiments.
