The title compound [Cu(bbtz)(HCOO)2(H2O)2]n (bbtz = 1,4-bis(1,2,4-triazol-1- ylmethyl)-benzene) was synthesized by the reaction of Cu(HCOO)2 and bbtz in methanol/H2O solution and its structure was determined by single-crystal X-ray diffraction. Crystal data: C14H18CuN6O6, monoclinic, space group P21/c, a = 9.651(2), b = 10.380(2), c = 9.368(2) , β = 112.905(5)°, V = 864.5(3) 3, Mr = 429.88, Z = 2, Dc = 1.651 g/cm3, F(000) = 442, μ = 1.311 mm-1, the final R = 0.0305 and wR = 0.0856 for 1891 observed reflections with I > 2σ(I). X-ray crystal-structure analysis suggests the central copper atom of the title compound is six-coordinated in a distorted octahedral geometry by two nitrogen atoms from two bbtz ligands as well as four oxygen atoms from two H2O and two HCOO-. The copper atoms are linked by bridging ligand bbtz to form a one-dimensional chain. There are intra- and interchain hydrogen bonding interactions between hydrogen atoms of coordinated water and uncoordinated oxygen atom of HCOO-.