  In the superconductor LaRu$_3$Si$_2$ with the Kagome lattice of Ru, we have
successfully doped the Ru with Fe and Co atoms. Contrasting behaviors of
suppression to superconductivity is discovered between the Fe and the Co
dopants: Fe-impurities can suppress the superconductivity completely at a
doping level of only 3%, while the superconductivity is suppressed slowly with
the Co dopants. A systematic magnetization measurements indicate that the doped
Fe impurities lead to spin-polarized electrons yielding magnetic moments with
the magnitude of 1.6 $\mu_B$\ per Fe, while the electrons given by the Co
dopants have the same density of states for spin-up and spin-down leading to
much weaker magnetic moments. It is the strong local magnetic moments given by
the Fe-dopants that suppress the superconductivity. The band structure
calculation further supports this conclusion.
