One compound with N-(4-pyridylmethyl)imidazole liand, [Co(pyim)2(N3)2]n 1(pyim = N-(4-pyridylmethyl)imidazole), was synthesized and structurally characterized. Compound 1 crystallizes in triclinic, space group P21/c with a = 8.090(3), b = 16.109(3), c = 8.590(3), B= 117.800(12)o, V = 990.3(5) A3, Z = 2, Mr = 461.37, Dc = 1.547 g/cm3, F(000) = 474, μ = 0.901 mm-1, the final R = 0.0381 and wR = 0.0950 for 1581 observed reflections with I > 2A(I). In this compound, the unique Co(Ⅱ) resides at a crystallographic inversion center and exhibits an octahedral coordination geometry. The adjacent Co(Ⅱ) ions are connected by the pyim ligands to form a 2D layer structure. The layers are stacked in an ABAB mode and reinforced by the weak interlayer C–H···N hydrogen bonds and π-π stacking to give a 3D architecture. The thermal property and electrochemical property of compound 1 have also been studied. One compound with N- (4-pyridylmethyl) imidazole liand, [Co (pyim) 2 (N3) 2] n1 was synthesized and structurally characterized. Compound 1 crystallizes in triclinic space group P21 / c with a = 8.090 3, b = 16.109 3, c = 8.590 3, B = 117.800 12, V = 990.3 A3, Z = 2, Mr = 461.37, Dc = 1.547 g / cm3, F (000) = 474, μ = 0.901 mm-1, the final R = 0.0381 and wR = 0.0950 for 1581 at 1581 observed reflections with I> 2A (I). The adjacent Co (Ⅱ) ions are connected by the pyim ligands to form a 2D layer structure. The layers are stacked in an ABAB mode and reinforced by the weak interlayer C-H ··· N hydrogen bonds and π-π stacking to give a 3D architecture. The thermal property and electrochemical property of compound 1 have also been studied.