The IR spectra of gelatins with added Ag⁺ ions were studied in order to understand the character of the interaction between silver ion and gelatin. It was found that the amino, imino and thioether groups were primary silver-binding sites of gelatin. Probably, methionine sulphone was also involved in some types of gelatins. Besides, Ag⁺ ion distribution in gelatin macromolecule was investigated with respect to molecular weight.