Introduction of amidoxime groups into cellulose substrate was investigated by reaction of cyano-group-containing celluloses such as cyanoethylcellulose (CE-Cell) and acrylonitrile-grafted cellulose (G-Cell) with hydroxylamine at 70 degrees C in water medium (pH = 7.0). Dissolving pulp from softwood was used as the cellulose sample, and photografting was applied to the preparation of G-Cell, where hydrogen peroxide was used as a photoinitiator. Degree of substitution (DS) of CE-Cell and percent grafting of G-Cell employed were less than 1.5 and 40, respectively. The amidoximation of CE-Cell proceeded easily, and the amidoxime content increased with increasing the reaction time and increasing the concentration of hydroxylamine, but the amidoxime content of G-Cell decreased significantly at longer reaction time. The amidoximated samples prepared by CE-Cell exhibited an ability to adsorb metal ions such as Cu2+, Ni2+ and Co2+, and the adsorbed amount of Cu2+ was highest among the three metal ions. Moreover, the adsorption of Cu2+ varied depending on the DS of CE-Cell. That is, the adsorption ability was reduced when the sample was prepared using CE-Cell with higher DS. The amidoximated samples prepared from G-Cell showed adsorption of Cu2+ Similar to samples prepared by CE-Cell with lower DS, irrespective of percent grafting.