The title compound [Cd(C20H14N4)2Cl2] 1 was synthesized via the hydrothermal reaction of CdCl2·7H2O and NaOH with 1,3-bis(benzimidazol-2-yl)benzene (BMB), and characterized by elemental analysis and infrared spectra. The crystal of 1 crystallizes in monoclinic, space group C2/c with a = 21.021(6), b = 9.489(3), c = 18.302(6), β = 108.686(6)o, V = 3458.2(19)3, Z = 4, C40H28CdN8Cl2, Mr = 804.01, Dc = 1.544 g/cm3, F(000) = 1624 and μ(MoKα) = 0.829 mm-1. The final R = 0.0306 and wR = 0.0779 for 3334 observed reflections with I 〉 2σ(I) and R = 0.0796 and wR = 0.0360 for all data. The cadmium atom is four-coordinated by the BMB ligands and Cl atom with a tetrahedral geometry. The extensive N-H···N hydrogen bonding interactions are observed in the structure, which further extend the [Cd(C20H14N4)2Cl2] units into a 1D structure. The thermogravimetric analysis measurement showed that compound 1 has thermal stability as no strictly clean weight loss step occurred below 425 ℃.