  We have studied the SUSY scale dependence of supersymmetric radiative
corrections to bottom quark mass on the branching ratio of $B_s^0 \to
\mu^+\mu^-$ and its impact on the cMSSM parameter space. The supersymmetric
radiative corrections to bottom quark mass is in general evaluated at the SUSY
scale, which is normally considered to be the geometric mean of stop masses.
Then, the running of bottom quark mass is considered from the SUSY scale to the
matching scale $M_W$ of the effective Hamiltonian which describes this decay.
It is found that the branching ratio varies drastically with the SUSY scale.
Typically the $Br[B_s^0 \to \mu^+\mu^-]_{\rm untagged}$ varies $\sim 0.6 \times
10^{-9}$ due variation of bottom quark mass $\sim 35\%$ with the SUSY scale and
these changes are very significant compared to their present uncertainties in
the measurements. Moreover, these variations are very larger at the regions of
parameter space which are favorable for producing higgs mass around 125 GeV.
Finally, the confrontation of cMSSM with $B_s^0 \to \mu^+\mu^-$ is drastically
relaxed if one lowers the SUSY scale and a significantly large parameter space
becomes allowed in the phenomenologically interesting regions.
