Two new μ-oxamido-bridged heterobinuclear complexes have been synthesized and identified as [Cu(dmoxpn)Mn(Me2phen)2](ClO4)2 (1) and [Cu(dmoxae)Mn(Me2phen)2](ClO4)2 (2), where Me2phen denotes 2,9-dimethyl-1,10-phenanthroline; dmoxpn and dmoxae represent N,N -bis[3-(dimethylamino)-propyl]oxamido and N,N’-bis[2-(dimethylamino)ethyl]oxamido dianions, respectively. Based on elemental analyses, conductivity measurements, IR and electronic spectra studies, it is proposed that the two complexes have oxamido-bridged structures consisting of a copper(Ⅱ) and a manganese(Ⅱ) ions, which have a square-planar environment and a distorted octahedral environment, respectively. The electronic reflectance spectra indicate the presence of exchange-coupling interaction between bridging copper(Ⅱ) and manganese(Ⅱ) ions. Variable-temperature magnetic susceptibility (4.2-300 K) measurements of (1) and (2) complexes revealed the occurrence of an intramolecular antiferromagnetic interaction between the adjacent manganese(Ⅱ) and copper(Ⅱ) ions through the oxamido bridge within each molecule. On the basis of spin Hamiltonian, H=-2JS1S2 the magnetic analysis was carried out for the two complexes and the spin coupling constant (J) was evaluated as -26.9cm-1 for (1) and -38.2cm-1 for (2). The influence of the chelate ring arrangement around the copper(Ⅱ) in the copper(Ⅱ)-manganese(Ⅱ) heterobinuclear complexes on magnetic interactions between the metal ions of this kind of complexes is also discussed.