The strategy of "complex as ligand" allowed us to synthesize three new _-oxalatobridged heterotetranuclear complexes identified as [Cu3Fe(ox)3(Me2bpy)3](ClO4)3 (1), [Cu3Fe(ox)3(Me2phen)3](ClO4)3 (2) and [Cu3Fe(ox)3(phen)3](ClO4)3 (3), where ox represents the oxalato dianions; Me2bpy, Me2phen and phen stand for 4,4_-dimethyl- 2,2_-bipyridine, 2,9-dimethyl-1,10-phenanthroline or 1,10-phenanthroline, respectively. These complexes are the first examples of [Cu3 IIFeIII] species bridged by oxalato groups. Based on elemental analyses, molar conductivity and magnetic moment (at room-temperature) measurements, IR, ESR and electronic spectral studies, these complexes are proposed to have oxalato-bridged structure consisting of three copper(II) ions and an iron(III) ion, in which the iron(III) ion has an octahedral environment, and the three copper(II) ions have a square-planar environment. The complexes (1) and (2) were further characterized by variable-temperature magnetic susceptibility (4.2~300 K) measurements and the observed data were simulated by the equation based on the spin Hamiltonian operator, _ _ _ _ _ _ _ H= 2J(S S S S S S Cu1 Fe Cu2 Fe Cu3 Fe Ĺ + Ĺ + Ĺ ), giving the exchange integrals J = -9.15 cm-1 for (1) and J = -8.79 cm-1 for (2). The results indicate the presence of an antiferromagnetic spin-exchange interaction between the copper(II) and iron(III) ions through the oxalato-bridge in both complexes (1) and (2).