Abstract: Blend films of water-insoluble silk fibroin(SF) powder and medical polyurethane were produced by the method of immersion-precipitation phase transformation.These blend films with different powder contents were investigated on the change of their surface morphology,water absorption,water vapor permeability,water contact angle,mechanical properties and IR spectrums.The results showed that,with increasing of water-insoluble silk fibroin powder content,blend films′ surface changed gradually from dense to loose with emergence of microporous,meanwhile the silk fibroin powder was uniformly dispersed in the films without apparent agglomeration,which suggested that they had good compatibility with each other.In addition,elongation at break and modulus of the blend films decreased to certain extent when compared with pure PU films,but their water absorption and water vapor permeability were gradually raised with increasing of water-insoluble silk fibroin powder content;films′ water contact angle declined,which suggested that their hydrophilicity was also gradually raised.