Abstract: The silk fibroin/CaSiO3 composite nanofibers with interconnected pore structures were fabricated via electrospinning. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy analysis showed that the structure of SF was Silk II. The results of field emission scanning electron microscopy (FESEM) showed that the diameters and porosities of the composite nanofibers were 200-400nm and about 78%, respectively. The surface hydrophilicities of the composite nanofibers were improved compared with that of pure SF nanofibers. The samples were soaked in simulated body fluid (SBF) and Tris-buffer to investigate their bioactivities and degradabilities, respectively. After soaking in SBF for 7 days, the surfaces of the composite nanofibers with 20% wt CaSiO3 were covered by hydrocarbonate apatite layer. The degradability of this sample reached 42.4% after soaking in Tris-buffer for 12 weeks. The addition of CaSiO3 into the silk fibroin nanofibers could improve in vitro bioactivity of the composite nanofibers and provide a promising opportunity to widen potential application of silk fibroin in bone tissue engineering.