Semicoking oil was obtained from tires only and from kukersite with addition of tires in solid heat-carrier unit SHC-3000 at Estonian Power Plant in Narva. Chemical composition of these oils has been studied using thin-layer and gas-liquid chromatography. The semicoking oil obtained from tires only contains 84.8% of hydrocarbons, 17.4% of which are nonaromatic compounds. Treating kukersite together with tires improves oil quality, makes it lower boiling and more unsaturated, increases the content of nonaromatic compounds in oil up to 29.8%, and so brings its composition closer to that of commercial liquid fuel.