  We demonstrate the different effect of strange impurities ($\Lambda$ and
$\Xi$) on the static properties of nuclei within the framework of the
relativistic mean-field model. Systematic calculations show that the gluelike
role of $\Lambda$ hyperon is universal for all $\Lambda$-hypernuclei
considered. However, $\Xi^-$ hyperon has the gluelike role only for the protons
distribution in nuclei, and for the neutrons distribution $\Xi^-$ hyperon plays
a repulsive role. On the other hand, $\Xi^0$ hyperon attracts surrounding
neutrons and reveals a repulsive force to the protons. Possible explanations of
the above observation are discussed.
