In this paper, P(LLA-CL)/Silk fibroin (SF) nano-yarns were papered by a modified electrospinning method, they were further to combine with SF to give a fiber reinforced sponge by freeze-drying, which was suppose to be used for bone tissue engineering. Fiber reinforce is an effective method to increase the strength of materials. SF and P(LLA-CL) have both biocompatibility and slower degradation rate, providing a longer time for new osteogenic tissue formation. Structure and morphology of the composites were observed by scanning electron microscope (SEM), which showed they had an interconnected porous structure. Fourier transform infrared spectrum(FTIR)and X-ray diffraction( XRD) were used into this study to determine chemical component of these composites and crystal structure. After been treated with 75% ethanol vapor for 6 h, the scaffolds became water-resistance. FTIR and XRD analysis showed that SF matrix of the composites had transformed from random coil or alpha-helical to beta-sheet structure.