Abstract: The regenerated silk fibroin(SF) was modified by Genipin cross-linking, and then was made into cross-linked nanofibrous membranes via electrospinning. The structure and properties of nanofibers were characterized and tested by use of FE-SEM, FTIR, XRD, TGA and tensile tester. The results show that the degree of cross-linking, average diameter of nanofibers and standard deviation increase with the increasing of Genipin mass ratio. And the crystal structure of SF nanofibers is not influenced by Genipin cross-linking, but thermal properties are improved. Under room temperature, the mechanical properties of SF nanofibrous membranes are enhanced with the increasing of Genipin mass ratio from 2% to 15%. And the mechanical property is better when the Genipin mass ratio is 10%, the tensile strength and breaking strain are 19.6 MPa and 5.9% respectively. The tensile strength and breaking strain of SF nanofibrous membranes first increase and then decrease with the rising of tensile temperature from 40 ℃ to 200 ℃, the mechanical property is better at 80 ℃, the tensile strength and breaking strain are 41.6 MPa and 8.6% respectively.