A new Cu(II) complex, [Cu₄Cl₆O(1-TrTz)₄] where 1-TrTz is 1-trityl-1H-[1,2,4]triazole, was synthesized by the reaction of 1-trityl-1H-[1,2,4]triazole with two hydrated cupric chlorides, and its structure was characterized by X-ray single-crystal diffraction. [Cu₄Cl₆O(1-TrTz)₄] is of monoclinic system, space group P2₁/c, a = 12.5024(13), b = 26.400(3), c = 28.588(3) Å, β = 112.807(4)°, V = 8698.1(16) ų, Z = 4, ρ_calc = 1.411 g/cm³, μ = 1.265 mm^–1, F(000) = 3772, the final R = 0.1293 and wR = 0.3644 for 55774 observed reflections (I > 2s(I)), R(all data) = 0.1972, wR(all data) = 0.3989, completeness to theta of 25.242 is 99.9% and GOF = 1.103. In the structure of [Cu₄Cl₆O(1-TrTz)₄], the central O atom is tetrahedral and is coordinated with four Cu atoms. The distance between copper and oxygen bond is 1.909(6) Å. In addition, the catalytic property of this complex was investigated and it could effectively catalyze the Ullmann coupling reaction of various (hetero)aryl chlorides with azoles.