Alginate/N-Succinyl-chitosan (SCS) blend fibers, prepared by spinning their mixture solution through a viscose-type spinneret into a coagulating bath containing aqueous CaCl2, were studied for structure and properties with the aid of infrared spectroscopy (IR) and X-ray diffraction (XRD). The results indicated a good miscibility between alginate and SCS, because of the strong interaction from the intermolecular hydrogen bonds. The best values of the dry tensile strength and breaking elongation were obtained when SCS content was 30 wt %. The wet tensile strength decreased with the increase of SCS content, and the wet breaking elongation achieved maximum value when the SCS content was 30 wt %. Introduction of SCS in the blend fiber improved water-retention properties of blend fiber compared to pure alginate fiber. Antibacterial fibers, obtained by treating the fibers with aqueous solution of silver nitrate, exhibited good antibacterial activity to Staphylococcus aureus. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2151-2156, 2010