  We report the first search for the penguin-dominated process $B_{s}^{0}
\rightarrow \eta^{\prime} X_{s\bar{s}}$ using a semi-inclusive method. A 121.4
$\mathrm{fb}^{-1}$ integrated luminosity $\Upsilon(5S)$ data set collected by
the Belle experiment, at the KEKB asymmetric-energy $e^+e^-$ collider, is used.
We observe no statistically significant signal and including all uncertainties,
we set a 90\% confidence level upper limit on the partial branching fraction at
1.4 $\times$ 10$^{-3}$ for $M(X_{s\bar{s}})$ $\leq$ 2.4 GeV/$c^{2}$.
