Silk fibroin had various applications especially outstanding for drug delivery due to its protein component, biocompatibility and biodegradability. In this paper, silk fibroin particles were prepared via self-assembly. Their sizes and appearances could be modified by adjusting of volume ratios among poly vinyl alcohol (PVA), silk fibroin and ethanol. Regular silk particles were formed in PVA solution when the volume ratio of silk to ethanol ranged from 2 to 20. Preparation pathways could be concluded as 1) mixing ethanol with silk fibroin solution, 2) blending the silk fibroin/ethanol solution with PVA, 3) freezing the ternary solution for 48 h and collection of silk fibroin particles via thaw and centrifugation. Silk particles with various appearances were also obtained by addition of concentrated PVA solution. Silk particles reported have potential as drug delivery carriers in a variety of biomedical applications. (C) 2011 Elsevier B.V. All rights reserved.