Reciprocal solubility of gasoline and gasoline fractions in ethanol depending upon the aromatic hydrocarbon content in them has been investigated. Conditionally the ternary system "paraffin-naphthenic hydrocarbonsaromatic hydrocarbon-ethanol" demonstrates a bounded solubility with two pairs of the components. Ethanol solubility in hydrocarbons is only 1-3 %. The hydrocarbons solubility in ethanol depends upon water content in it and the temperature. The curve characterizing the hydrocarbons solubility in ethanol at triangular diagram is atypical: it has the concave shape versus the usual convex one.