The zinc (II) complexes, which contain oligopolyamide and bis(2-benzimidazolylmethyl)amine (IDB) conjugated by flexible linker, have been successfully synthesized, characterized, and evaluated as DNA cleavage agents. The cleavage activity of these complexes on DNA was studied by electrophoresis. The results showed that the cleavage activity of zinc (II) complexes was enhanced comparing with those without oligopolyamide. Specially, at a high reaction concentration (1.2mM), Zn (II) complex can cleave the plasmid DNA bearing some selectivity. Further, the spectroscopic data suggested that Zn (II) complexes with oligopolyamide backbone possessed A-T (adenine and thymine) rich sequences preference.