Dithiocarbamate (DTC) -type chemically modified chitosan was synthesized by incorporating functional groups of dithiocarbamate onto polymer matrices of chitosan, and the adsorptive separation characteristics of precious metals were investigated, among which silver in particular was examined in detail. DTC-chitosan is found to exhibit high selectivity not only towards silver but also towards gold and palladium. The adsorptive separation characteristics of DTC-chitosan are superior to raw material chitosan and commercial chelating resin containing the same functional group(DTC), which is considered to be attributable to synergistic effects by a combination of dithiocarbamate group and polymer matrices of chitosan. Furthermore, adsorptive recovery of silver from waste cynaide and noncyanide solution for silver plating is found to be achievable. The maximum adsorption capacity of DTC-chitosan for silver is 3.6 mol./kg. From the above-mentioned results, it is concluded that DTC-chitosan is a practical candidate for an adsorbent.