By photometric method complex formation of Mo(VI) with of 2,3,4-trihydroxybenzol-4'-sulfoazonaphthalene in the presence surface-active substances (CPCl – cetylpyridine chloride, CPBr – cetylpyridine bromide, CTMPABr–cetyltrimethylammonium bromide) has been studied. The optimal condition of formation composition of differently ligand complexes have been established. The molar coefficient of absorption and submission interval to the gage schedule are defined. Influence of outside ions on a complex formation is studied. The developed technique is used for determination of Mo(VI) in wastes waters.