[en] A new Cu(II) complex with bi-[N-(propionic acid)] terephthalal diacythydrazon (H4L) was obtained by the reaction of CuCl 2H/sub 2/O and H/sub 4/ L in 1:1 pyridine and methanol. According to X-ray diffraction, the product was a binuclear complex, [Cu/sub 2/L(pyridine)6] 2H/sub 2/O. Each Cu(II) in the complex is six-coordinated by one N and two O atoms of H/sub 4/ L and three N atoms from pyridine. The coordination polyhedron around Cu(II) can be described as an octahedron with slightly distorted. In addition, antibacterial activities of the complex against coliform were investigated.The results showed that the inhibit rates of binuclear complex were 83% against coliform. (author)