A novel supramolecular complex [Cu₂(phon)₂(μ₂-Cl)₂Cl₂]·DMF was synthesized by situ reaction of 1,0-phenanthroline-5,6-dione with Cu(Ⅱ) salt. The complex is characterized by X-ray diffraction analysis, elemental analysis, IR and UV-visible spetra. In the dinuclear Cu(Ⅱ) complex, the Cu(Ⅱ) ion is in a distorted square pyramidal geometry(τ= 0.12) with four donor atoms (N₂Cl₂) in the basal plane and one chlorine atom occupying the apical position. In addition, hydrogen bonds (C—H…Cl and C—H…O ) and π-π intermolecular interactions link these dinuclear molecules into two-dimensional layers.