Specific features of the content and composition of heteroatomic compounds in oils from deposits of the Jurassic complex in the southeastern part of Western Siberia were studied. A high redox potential in the sedimentation basin was shown to favor the generation of oils with a low content of nitrogen-, oxygen-, and sulfur- containing compounds. The influence of an increase in the thermal maturity on the content of these compounds in the oils formed from organic matter deposited under different oxidation-reduction conditions was considered.