Abstract: A series of —NCO terminated polyurethane(PU) prepolymers were synthesized using polyethylene isophorone diisocyanate(IPDI), glycol(PEG), polypropylene glycol(PPG) as raw materials. By mixing with selfmade silk fibroin(SF) aqueous solutions, SF-PU hydrogels were prepared. The synthesizing process of SF-PU hydrogels was studied by infrared spectroscopy(FT-IR), scanning electron microscope(SEM). Swelling dynamics, and the relationship between structure and performance were also researched. Results show that nice swelling responsed SF-PU hydrogels with three dimensional structure were prepared successfully.