  We study the effect of non-universal $Z'$ boson on the rare leptonic decay
modes of $B_s^*$ mesons, mediated by $b arrow sll$ quark transition. Rare B
decays are sensitive to various new physics operators. As B mesons are
composite particles, such decay modes of the excited states are ideal for
probing new physics beyond the standard model. We have constrained our model
parameters from $B_(s,d)-$ {B bar(s,d)}$ mixing data to predict the lepton
polarization asymmetry of $B_(s,d)^*$ arrow ${\mu}^+ {\mu}^-$ channel. It is
found that this asymmetry deviates from its SM prediction along with the
$Z'$effect
