N,O-carboxymethyl　chitosan　(NOCC)　composite　nanofiltration　membranes　crosslinked　by　ECH　were　developed　using　a　method　of　coating　and　crosslinking,　where　an　epichlorohydrin/ethanol　96.7%　(0.067　M　KOH)　solution　was　used　as　the　crosslinking　agent.　The　structure　and　the　morphology　of　the　resulting　membrane　were　characterized　by　attenuated　total　reflection　infrared　spectroscopy　(ATR-IR)　and　environmental　scanning　electron　microscopy　(ESEM).　The　effects　of　preparation　conditions　on　the　rejection　performance　of　the　resulting　composite　membrane　were　also　investigated.　At　20C　and　0.40　MPa　the　rejections　of　the　resulting　membrane　to　Na2SO4　and　NaCl　solutions　(1000　mg　L-1)　were　90.4%　and　27.4%,　respectively,　and　the　permeate　fluxes　were　7.9,　and　10.8　kg　m-2h-1,　respectively.　The　rejections　of　this　kind　of　NOCC/PSF　composite　NF　membrane　to　the　inorganic　electrolyte　solutions　decreased　in　the　order　of　Na2SO4,　NaCl,　MgSO4,　and　MgCl2.　©　2008　Elsevier　B.V.　All　rights　reserved.