The non-accession of states to the Rome Convention does not render them immune to the jurisdiction of the International Criminal Court because their presence within the Assembly of States Parties gives them many advantages. The aim of the present study is to reveal the effect of the States Parties on the International Criminal Court. Although, this Assembly is not within the divisions of the International Criminal Court, but it has the privilege to supervise over the mechanism of the International Criminal Court's procedures, though, some go so far beyond this by calcimining that this Assembly is the mastermind of the International Criminal Court. This is why, we need to highlight the emergence of this Assembly, its specialization, its influence on the settlement of the disputes interpretation as well as the adjustment and the execution between the States Parties and how to solve these disagreements, this is because it is the legislature duty of this Assembly. Thus, the investigation of the present study attempts to show the fundamental role of this Assembly on the International Criminal Court. This can be accomplished throughout an extrapolation of the legal texts of the related topic and analyse them. The study concludes that the Assembly of States Parties has just a relative effect on the disputes interpretation of the fundamental system of the International Criminal Court. Although, the Assembly of States Parties may on the basis of the powers granted to it, establish its own judicial body by which it can solve the disagreements between the States Parties that related to disputes interpretation, instead of issuing uncommitted recommendations or escalate the dispute to the International Justice Court so as to prevent political interference in the tasks of the International Criminal Court.