Bio-nanocomposite was prepared by impregnation of bacterial cellulose into the poly(3-hydroxybutyrate) (PHB). The morphology was examined by field emission scanning electron microscopy, which showed the well-dispersed bacterial cellulose nanofibrils in PHB. The changes in the crystallinity of PHB caused by incorporating the bacterial cellulose were investigated by X-ray diffraction. The result indicates that the bacterial cellulose nanofibrils probably help the PHB molecules to crystallize. An increase in the mechanical properties was observed by impregnating bacterial cellulose as reinforcement into the PHB matrix. The biocompatibility of nanocomposite was preliminarily evaluated by cell-adhesion studies using Chinese Hamster Lung (CHL) fibroblast cells. The cells incubated with nanocomposite scaffold for 48 h were capable of forming cell adhesion and proliferation, which shows much better biocompatibility than pure PHB. (C) 2010 Elsevier B. V. All rights reserved.