Two exo‐cyclic 11‐vertex isocloso ruthenaborane clusters [(PPh3)(p‐ClPhCO2)2RuB10H8] (1) and [(PPh3)2Ru(PPh3)(p‐ClPhCO2)RuB10H9]·0.5C5H12·H2O (2·0.5C5H12·H2O) have been synthesized and characterized by elemental analysis, FT‐IR, NMR spectra and single‐crystal X‐ray diffraction analysis. The structure analysis shows that both of the clusters are based on an 11‐vertex closo‐type {RuB10} cluster‐geometry with the nine‐coordinate metal atom occupying the six‐connected apical position. In cluster 1, the metal center has three exo‐polyhedral ligands, one triphenylphosphine and two dative oxygen atoms of para‐chlorobenzoates which form two exo‐cyclic five‐membered Ru‐O‐C‐O‐B rings with the other oxygen atoms bonding to B(2) and B(3) atoms. The cluster 2 also has one exo‐polyhedral para‐chlorobenzoate to form one exo‐cyclic five‐membered Ru‐O‐C‐O‐B ring in one side. There is another exo‐polyhedral ruthenium atom bonded to the cluster center {RuB10} via one Ru‐Ru linkage and two RuHμB bridges forming a closed exo‐polyhedral tetrahedron configuration in the other side.