Taking into consideration the fact that there are a small percentage of humic acids in a free state in soils and they join with the mineral part of the soil, the trial of the synthesis of the preparations of humic acids with bentonite and illite was experimented. Some physicochemical properties and their degree of reaction were characterized. The measurements of the surface area were made in the organo-mineral associates. Using the adsorption method of water vapour BET on the basis of the beginning part of the adsorption isotherm in 20°C. The physico-chemical properties of the associates of illite and bentonite with humic acids, β-humus with humic acids and β-humus with different pH were presented. The results of surface area and the molar energy adsorption were particularly discussed. At the beginning, it was thought that the highest degree of reaction of humic acids with minerals should be set when pH equals the pH of the moment when humic acids are precipitated from the liquids as the precipitate. After studying the results something else was stated, the surface area of illite after adding the humic acids with all kinds of pH becomes smaller. The falling surface areas of the all combinations of the organo-mineral connections proves the different degree of their reactions and probably the part mineral hydrofobization. It turned out that the degree of reactions of humic acids preparations with mineral depends on pH and it is the highest for all combinations for pH 4.