One novel heterometallic trinuclear complex of macrocyclic oxamide [Ni(CuL)(2)(HBTC)H2O] (I) (H2L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclopentadeca-7,13-dien; H3BTC = 1,3,5-benzenetricarboxylic acid) has been solvothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, XRD, and single-crystal X-ray diffraction. The crystals crystallize in the monoclinic system, space group P2(1)/c, a = 11.435(3), b = 20.646(5), c = 18.430(5) , beta = 94.131(4)A degrees. The structure of I has oxamido-bridged trinuclear [Cu (2) (II) Ni-II] units and consists of two-dimensional supramolecular architecture formed by strong intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I was investigated and discussed in detail.