Abstract: The polyurethane (PU) with different carboxyl contents was prepared using polytetrahydrofuran glycol, 4,4-diphenylmethane diisocyanate, 1,4-butanediol and 2,2-dimenthylol propionic acid (DMPA) as raw materials, and the carboxylate PU ionomer was synthesized through neutralization of zinc acetate and PU with carboxyl group. The effects of metal ions on the structure and mechanical properties of PU ionomers were investigated by FT-IR, DSC, AFM and tensile test. The results show that the hydrogen bonding in PU ionomer increased when the metal ion was introduced into the PU. The tensile strength and the degree of microphase separation between soft segment and hard segment in the PU were also enhanced. The oval-shaped microphase revealed the existence of ion clusters interaction in the PU ionomer.