We study possible CP-violation effect of the Higgs to $Z$ boson coupling
at the future $e^+ e^-$ collider (ILC). We find that the azimuthal angular distribution of the muon pair, produced by $e^+ e^- \rightarrow H Z \rightarrow H \mu^+ \mu^-$, can be sensitive to such a CP-violation effect when we apply initial transversely polarized beams. Based on this angular distribution, we construct a CP sensitive asymmetry, and obtain this asymmetry by \texttt{Whizard} simulation. By comparing the SM prediction with 2$\sigma$ range of this asymmetry, we estimate the discovery limit of the CP-odd coupling in $HZZ$ interaction.