Theory is the most important tool for analyzing human actions and phenomena of international relations. Practice Theory is one of the most recent efforts in the field of theorizing international relations and has attracted many fans. Rather than being considered as a structured and articulated theory belonging to a specific person, Practice Theory, is considered a new theoretical field with its own metatheoretical issues. Generally; The main focus of This Theory is on the analysis of international political relations by highlighting specific procedures and patterns in which human actions take place. Undoubtedly, the most important metatheoretical element of any theoretical framework; It is its ontological basis. Based on this, in this research, by describing the ontological foundations of the Practice theory, we are trying to answer this basic question: What are the criticisms and in what dimensions are the ontological foundations of the Practice theory and, if possible, how can these flaws be resolved? The tested hypothesis is as follows: despite the claim of its supporters, the Practice Theory does not have an independent ontology and the emphasis on common bodily procedures and standard verbs in international interactions is ultimately another expression of the construction of the social world; By adopting a constructivist approach and basically a deep constructivist understanding, it explains all the ontological claims of Practice Theory well, and in fact, This Theory should be examined under constructivism and not even neo-constructivism. The method of conducting this research is Analytical-Explanatory and with an emphasis on criticizing the views of practicalists.