The title complex Cu(L)2 (HL=o-vanillin hydrazone) was synthesized by the reaction of Cu(CH3COO)2·H2O with o-vanillin hydrazone in the ethanol. It was characterized by elemental analysis, IR and X-ray single crystal structure analysis. The crystal of the title complex [Cu(C8H9N2O2)2] belongs to triclinic, space group P1 with a=0.457 57(8) nm, b=1.333 2(2) nm, c=1.386 0(3) nm, α=108.955(2)°, β=90.868(2)°, γ=95.859(2)°, V=0.794 4(2) nm3, Z=2, Dc=1.647 Mg·m-3, μ=1.406 mm-1, F(000)=406, and final R1=0.035 1, wR2=0.096 3. The complex comprises a four-coordinated copper(Ⅱ) center, with an N2O2 planar coordination environment. The molecules are packed in one-dimensional chain polymer though the N…Cu interaction from adjacent molecules, respectively.