The author thoroughly investigates the preconditions that have allowed a science of political decision making to get formed and institutionalized into a particular discipline within a complex of policy sciences. A.A.Degtyaryov suggests a definition for the subject of the theory of political decision making (TPDM), from which (definition) it follows that the TPDM has a fundamental, as well as an applied aspect and thus appears to be a link between fundamental and applied knowledge. A considerable part of his article having been assigned for careful analysis of pioneering studies carried out by American researchers, the author finds it nevertheless appropriate, other considerations apart, to point out that toward the end of the past century the new scientific discipline had been gaining topicality outside America, too, and not only in Europe and Asia, but also in Russia.