The methods of dissolving Antheraea yamamai (A. yamamai) silk fibroin fibers and preparing the regenerated silk fibroin were studied. The molecular conformations of A. yamamai silk fibroin film treated by different concentration ethanol solution were investigated by XRD, FTIR, and Raman spectra. The results indicated that A, yamamai silk fibroin fibers could be completely dissolved in dense lithium thiocyanate solution at about 35 degrees C for 1 h. The initial regenerated film consisted of alpha-helix and random coil components. The aqueous ethanol treatment of the film resulted in significant increase in beta-sheet component and improvement of water resistance of the film. This effect was strongly dependent on ethanol concentration, and 60-80%, (w/w) ethanol was most effective. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116:461-467,2010