The principle 75 of the Constitution of Islamic Republic of Iran is one of the functional principles of this law which restricts the legislative competence of the Assembly and prevents the representatives of the Islamic Consultative Assembly to introduce proposals and suggestions which lead to reduction in public income or increase in public expenditure without determining a specific resource to compensate that reduction or increase.Although this principle seems obvious, there are practically numerous ambiguities in this regard and during the years of its implementation, many questions have been raised regarding the scope of the Assembly’s performance in implementing this principle. This issue has always led to some conflicts between the Assembly and the Guardian Council on the one hand, and the Assembly and the executive power on the other hand. Therefore, to answer the fundamental question of this article, namely the determination of the scope of the Islamic Consultative Assembly’s competence in implementing the principle 75 of the Constitution, it is strived with the emphasis on legal documents and by using the content analysis instrument to examine the limits of the principle 75 and the Assembly’s performance on its implementation. As the consequents indicate, the Assembly can’t introduce suggestions and pass proposals in contradiction with the principle 75. Nevertheless, given the existing legal vacuum, in case of passing such proposal and the objection of the Guardian Council regarding that, it can’t be referred to the State Exigency Council pursuant to the interpretive comment of the Guardian Council.