Without using any other reducing reagents or templates, a one-step approach for synthesizing dendritic Ag nanostructure by the treatment of sliver ions only in the presence of silk fibroin biomacromolecule is described. The morphology and structure of as-prepared silver nanodendrite are characterized, and its application for surface-enhanced Raman scattering (SERS) is also investigated. It has been found that the morphology of as-prepared Ag dendrite is dependent on the reaction duration, but not the concentration of sliver ions in the reaction process. SERS study shows that the silver nanodendrites give an intensive and enhanced Raman scattering when pyridine is used as a probing molecule. It is suggested that silk fibroin provides dual reductant and structure-directing roles to promote sliver ions forming shape-controlled nanostructures in high yield. (C) 2010 Elsevier B.V. All rights reserved.