Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature oil the properties of the composite membranes Was Studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, Xray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and -OH groups of n-HA and -NH2 or -OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence oil the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell Culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect oil the cell morphology, viability and proliferation and possess good biocompatibility. This Study makes the nHA/CS composite membrane be a prospective biodegradable GBR membrane for future applications. (C) 2008 Elsevier B.V. All rights reserved.