Degummed Antheraea pernyi silk fibroin (APSF) fibers were dissolved in a lithium thiocyanate solution that was dialyzed against distilled water for 3 days. Solution-cast APSF films were dissolved in hexafluoroisopropanol to prepare a spinning solution. Wet spinning was employed to prepare APSF filaments. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, solid-state C-13 cross-polarization/magic angle spinning nuclear magnetic resonance, and differential scanning calorimetry were employed to study the regenerated APSF filaments. The results showed a uniform distribution of molecular weights, and the largest one may have been greater than 200 kDa. The regenerated filaments contained beta-sheet, alpha-helix, and random-coil conformations, and their breaking strength was 52.20%, of the breaking strength of the native fibers. 2009 (C) Wiley Periodicals, Inc. J Appl Polym Sci 113: 2160-2165, 2009