The principles for the 3D/4D classification of drugs are introduced in this article. Based on these principles, new techniques for the reconstruction of complementary selfconsistent receptor fields for the classification of drugs, taking into account their multitautomeric and multiconformational states, are created. The series of examples of classification of drugs by their activity (active or nonactive), by their mechanisms of action, by their target and binding site and by the most important stages of their action are given. Prospects for rational drug design are highlighted.