Dinuclear metal carboxylates are interesting compounds, having a lantern-type (or paddlewheel-type) dinuclear core (Fig. 1) [1,2]. We have engaged in chemistry of metal carboxylates, paying attention to their magnetic properties. Ruthenium(II,III) carboxylates are in such cases, having three unpaired electrons in the metal-metal bond orbitals with large zero-field splitting. We prepared many metal-assembled complexes from dinuclear metal species to onedimensional polymeric chain compounds by application of bidentate linking ligands L to dinuclear metal carboxylates. In most cases, magnetic interaction between the dinuclear units is antiferromagnetic and the strength of the interaction depends on the linking ligand L [2-4]. In few cases, a ferrimagnetic interaction was observed for mixed-metal complexes with hexacyanidoferrate(III) and octacyanidotungstate(V) [2,5]. In this study, we extended these systems to mixed-metal complexes with tetracyanidometalate ion by using tetracyanidonickel(II) ion [Ni(CN)4]2– in order to obtain new metal-assembled complexes of ruthenium(II,III) carboxylate. Herein, we report on the magnetic properties of these complexes.