Abstract: Graphene oxide (GO) was added into silk fibroin (SF) glycerin (Gly) composite films via casting method to improve the properties of composite films. The SF-GO -Gly composite films were characterized by X-Ray Diffraction (XRD), ATR-Fourier Transform Infrared spectroscopy (ATR-FTIR), electronic universal testing machine, Field Emission Scanning Electron Microscopy (FESEM) and dissolution rate test to study the effect of GO. After adding GO, crystal form of SF matrix transferred from Silk I to Silk Ⅱ, tensile strength of composite films increased by 32% and dissolution rate of composite films decreased obviously after soaked in water at 37 °C. GO could act as nucleating agent in SF matrix.