The present study is a theoretical exploration that tries to provide ontological criteria, while conceptually explaining the principles and separating them from the basic principles, sub-principles, rules and partial practical patterns, to provide the possibility of scientific judgment about the position and relationship of concepts with each other. Then, it critiques and re-reads what is mentioned in the existing works in this field as "principles of Islamic diplomacy" based on the presented ontological principles. To achieve this goal, the three foundations of monotheistic thought, political thought and Islamic diplomacy are presented and seven key propositions are identified as principles derived from them and others as sub-rules and rules that come from the main propositions. Also, an attempt has been made in the form of a qualitative method and based on the principles of theoretical research method, to show the how of articulating the floating signifiers of Islamic diplomacy in the system of Islamic political thought and by drawing a final chart, the result of the research achievements is presented.