A lectin, Cyclina sinensis (Gmelin) (CSL), was isolated from hemolymph C. sinensis by ion-exchange on Cellulose DE52 and purified by gel filtration on Sephadex G-100 and HPLC on TSK gel G4000PW(XL). SDS-PAGE showed that the CSL protein had a molecular mass of 72 kDa, had consisted of 40 and 18 kDa subunits. The lectin activity of CSL was Ca2+-denpendent. The total carbohydrate content of CSL was found to be 16.2%. According to the principle of beta-elimination reaction, the oligosaccharide moiety and peptide moiety of CSL might belong to O-glucosidic linkage. CSL was found to agglutinate rabbit erythrocytes and yeast Saccharomyces cerevisiae. The hemagglutination activity was inhibited by GalNAc and Man. CSL was observed to promote the yeast cells growth and ethanol production by yeast cells. The number of yeast and ethanol production increased with increasing concentration of CSL. In addition, the nitric oxide (NO) production increased as CSL concentration increased. The results indicate that CSL can be a potential yeast stimulator in fermentation process. (C) 2012 Elsevier Ltd. All rights reserved.