Characteristic trends in the distribution of steranes, terpanes, n-alkanes, and isoprenanes in the Jurassic and Cretaceous oils of Kalmykia were studied. It has been shown that the distinctive features of these oils are increased relative concentrations of neoadiantane, diahopane, pregnanes, cheilanthanes, and n-alkanes and an almost undetectable presence of a naphthenoaromatic "hump" on the GLC chromatograms of the crude oils. Unlike the sterane indices, the terpane parameters make it possible to distinguish the Jurassic and Cretaceous oils. It was assumed that these oils are lacustrine in origin.