N,　O-carboxymethyl　chitosan　(NOCC)　composite　nanofiltration　(NF)　membranes　were　prepared　by　coating　and　cross-linking.　The　fermentation　effluent　from　a　wine　factory　was　treated　with　the　resulting　NOCC/polysulfone　(PSF)　composite　NF　membranes.　The　permeate　flux　and　the　removal　efficiencies　of　the　resulting　NF　membranes　for　the　color,　chemical　oxygen　demand　(CODCr),　total　organic　carbon　(TOC),　and　conductivity　of　the　fermentation　effluent　were　investigated　in　relation　to　the　driving　pressure,　the　feed　flow,　and　the　operation　time.　The　permeate　flux　and　the　removal　efficiencies　were　found　to　increase　with　the　increase　of　the　driving　pressure　or　the　feed　flow.　At　0.40　MPa　and　ambient　temperature　the　removal　efficiencies　were　95.5%,　70.7%,　72.6%,　and　31.6%　for　color,　CODCr,　TOC,　and　conductivity,　respectively.　The　membrane　was　found　to　be　stable　over　a　10-h　operation　for　the　fermentation　effluent　treatment.　©　2008　Chemical　Industry　and　Engineering　Society　of　China　(CIESC)　and　Chemical　Industry　Press　(CIP).