Abstract: Fibroin/polyamide blend fibers were electrospun with the mixture of 9% fibroin and 12% polyamide 6/66 copolymer formic acid solutions at 15 kV voltage and 15 cm distance from the tip of capillary to collecting screen(C-SD).The effects of polyamide content on the diameter and crystal of fiber and the mechanical properties of fiber mat were investigated.After being treated by ethanol,the morphology and performance of electrospun fibroin/polyamide fibers were analyzed.The results indicated that addition of polyamide in the fibroin formic acid solution not only decreased the diameter of fiber,but also improved its crystal and breaking strength of fiber mat.Electrospun fibroin/polyamide fibers treated by ethanol exhibited even swelling and higher crystallinity than as-spun ones,and the fiber mat was stronger and more stable in water.