A theoretical study on the magneto-structural correlation in binuclear Cu (Ⅱ) complexes bridged by the imidazolate anion has been performed using the broken-symmetry approach with the framework of density functional theory (DFT). The calculated results show that the variational trends of the magnetic coupling constant J with geometrical parameters are different for two models. The magnetic coupling constant J mainly depends on the Cu-N-C (im) bond angle ф and is insensitive to the variation of the Cu-N (im) distance and the dihedral angle a between the bridged imidazolate ring and copper coordination planes. The dependence of J on the angle ф in the two models shows that the J values are equal when the Cu-N-C(im) angle f 128.