The crystal structure of the complex [Cu(EDTB)].2Tos.4H 2 O.C 2 H 5 OH (EDTB=N, N, N', N' -tetrakis(2-benzimidazolylmethyl)-1,2-ethanediamine, Tos=4-methylbenzene-sulfonate ion) has been determined by X-ray diffraction method and refined by full-matrix least-squares methods to R=0.0688 and wR=0.2110 using 7802 reflections with I>2σ(I). The compound crystallizes in the triclinic space group P1. The lattice parameters are a=12.8720(10)Å, b=13.4879(9)Å, c=18.260(2)Å, α=107.991(2) o , β=107.803(2) o , γ=91.204(2) o and V=2847.4(4)Å 3 . Each Cu(II) ion is coordinated by four benzimidazole nitrogen atoms and two amine nitrogen atoms from EDTB molecule to form a distorted octahedron. Two 4-methylbenzenesulfonate ions play a role of un-coordinating counter-anions. The hydrogen-bonding interactions give rise to 2-dimensional layer structure. TGA, FT-IR, UV-Vis and CV were also used to characterize the complex.