A novel hyperbranched polyurethane (HBPU) finishing agent was prepared by graft copolymerization of hyperbranched poly (amine-ester) polyols (HPAE) and the isocyanate-terminated polyurethane prepolymer(PPU). The PPU was synthesized by step polymerization of isophorone diisocyanate (IPDI) with polyethylene glycol (PEG) and dibutyltin dilaurate (DBTDL) as catalyst. The FT-IR spectroscopy was used for the structural characterization. The thermal properties of HBPU were characterized by TGA. Microphase separation of HBPU film surface was studied by tapping-mode atomic force microscopy (AFM). Moreover, in contrast to 200-UT, the physical and mechanical properties of HBPU as finishing agent were investigated: curing time was decreased by 26.15% and the water vapor permeability was increased by 9.04%.