The process of dissolution of asphaltene-resin-wax deposits was investigated from the standpoint , of the heat of mixing. It was shown that, of the main constituent groups of asphaltene-resin-wax deposits, not only paraffin waxes and resins but also asphaltenes can form true solutions. The components isolated from the paraffin base showed the best solubility in kerosene and diesel fractions of crude oil.