[en] To find optimum conditions of forming the complexes suitable for extraction-photometric determination and for group concentration of ruthenium(4), interaction of ruthenium(4) with bivalent tin has been studied. It has been shown that formation of complexes depends on concentration of tin, HBr(HCl), temperature, and duration of complex formation. The existence of rose, brown, and yellow complexes of ruthenium(4) with bivalent tin has been established. Conditional molar coefficients of absorbing the complexes have been calculated. It has been shown that ruthenium(4) can be determined with the help of SnBr₂ by creating certain concentration conditions