A new Cu(Ⅱ) coordination polymer [Cu(inio)2(H2O)] (inio = isonicotinic acid N-oxide) with chemical formula C12H10CuN2O7 was prepared and its crystal structure has been determined by X-ray analysis. The complex crystallizes in the monoclinic system, space group C2/c with a = 12.455(3), b = 6.202(1), c = 16.555(3) ? b = 106.776(3), V = 1224.3(4) 3, Z = 4, Mr = 357.76, Dc =1.941 g/cm3, m(MoKa) = 1.827 mm-1, F(000) = 724, R = 0.0601 and wR = 0.1417 for 908 observed reflections (I > 2s(I)). The Cu(Ⅱ) atom is coordinated by an elongated square pyramid geometry. The deprotonated isonicotinic acid N-oxides form a double-bridge between each pair of Cu(Ⅱ) ions in trans form through two oxygen atoms from the carboxyl groups and two other oxygen atoms from the -NO groups, respectively, which leads to an infinite one dimensional chain. The two adjacent elongated Cu(Ⅱ) square pyramidal geometries are arranged in trans form in the same chain. The OH…O hydrogen bonds extend the chain structure into two-dimensional layers. A new Cu (II) coordination polymer [Cu (inio) 2 (H2O)] (inio = isonicotinic acid N-oxide) with chemical formula C12H10CuN2O7 was prepared and its crystal structure has been determined by X-ray analysis. The complex crystallizes in The monoclinic system space group C2 / c with a = 12.455 (3), b = 6.202 (1), c = 16.555 (3)? b = 106.776 (3), V = 1224.3 Mr = 357.76, Dc = 1.941 g / cm3, m (MoKa) = 1.827 mm -1, F (000) = 724, R = 0.0601 and wR = 0.1417 for 908 observed reflections (I> 2s (I) (Ⅱ) atom is coordinated by an elongated square pyramid geometry. The deprotonated isonicotinic acid N-oxides form a double-bridge between each pair of Cu (Ⅱ) ions in trans form through two oxygen atoms from the carboxyl groups and two other oxygen atoms from the -NO groups, respectively, which leads to an infinite one dimensional chain. The two adjacent elongated Cu (II) square pyramidal geometries are arranged in the same form chain. The OH ... O hydrogen bonds extend the chain structu re into two-dimensional layers.