A new dinuclear copper(Ⅱ) complex [Cu(CH_3COO)(C_7H_5N_4)(H_2O)]_2.3?5H_2O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallizes in the monoclinic space group P2_1/c, with a = 12.0188(7), b = 13.7993(8), c = 8.7488(5) A, β = 101.7350(10)°, V= 1420.67(14) A~3, D_c = 1.568 g/cm~3, Z = 1,F(000) = 690,the final GOOF = 1.145,R= 0.0437, and wR= 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ_2-μ~1;μ~0 3-(pyrid...