Surface microstructure of the CdS thin films, obtained by hydrochemical deposition technique and subjected to modifying them by exposure to an aqueous solution of lead acetate salts, including complexing agent, such as sodium citrate and ethylenediamine, were investigated by atomic force microscopy and scanning electron microscopy. It was shown that chemical composition and surface morphology of the films depends on the conditions of modification. It was found that lead occurrence in the film composition to form a solid solutions of substitution, presumably Pb x Cd 1− x S, occurs after modifications due to heterogeneous processes at the interface CdS solid/Pb 2+ solution. Fractal dimension of the investigated layers surface were determined.