The paper considers modeling of language subsystems as a unique method of scientific knowledge, appearing due to the high-level development of science. Modeling is substituting a particular component of the original object of scientific activity by its appropriate substitute, a model. Particular attention is given to the logical models of vocalism that can be used instead of common structural methods. These models can take into account not only the structure but also the substance and the function of phonological language elements, making them systemic models. Based on the conceptual idea of G. P. Melnikov, the founder of modern system linguistics, dealing with the modeling of Turkic vocalism, the researchers develop geometric models of Altaic, Khakass, Yakut and Tuva vocalisms. The geometric forms and structures of these models, reflecting the composition of the phonological system elements and the relations between them, allow one to correlate them with the general model of Turkic vocalism, the phonological system organization typical for the language family. Also, it becomes possible to compare and to identify the typological differences within the family of languages and thereby to deepen the understanding of the specific structure of a particular vowel system. In linguistics, modeling can be used to solve both theoretical and applied problems. Modeling is of particular importance in the typological description and comparison of languages. © 2019 Siberian Branch of the Russian Academy of Sciences, Institute of Philology. All rights reserved.