The objective of this study was to investigate the bleaching efficiency of chitosan/nano-silver composite fiber (CSF) compared with cotton fiber (CMF). The bleaching efficiency was analyzed by the weight loss and reflectance. The variation of tenacity and viscosity in various concentration of hydrogen peroxide and alkalis (soda ash, caustic soda) were observed. The molecular weight and tenacity of bleached CSF decreased as the hydrogen peroxide and alkali concentration increased, however significant change of bleaching efficiency was not determined.