In the Islamic Republic of Iran, there has been and there is a concern for demographical policies within the framework of the Law. A review of demographical policies of the Islamic Republic of Iran support the fact that these policies have passed through three stages. Regarding the importance of the quantitative aspect of the structure of demographical policies of the Islamic Republic of Iran, and the fact that most of the debates over and concerns for these policies in terms of quantity, particularly of birth or population control, this article has dealt with the legal foundations and documents related to this aspect of demographical policies of the Islamic Republic of Iran. The study of legal foundations and available documents related to the idea of population and demographic policies provides support to the fact that demographic policies in its quantitative aspect, whether one takes the high birth rate approach or birth control approach into consideration, do not pose any legal obstacle, but rather they provide foundations and ample documents which are accepted by the Law, just as the variability of the policies in different phases have not posed and do not pose any obstacles given the subject being in the state of fluidity or multi-dimensional. This is in line with Supreme leader Ayatollah Khamenei’s jurisprudential thoughts and views, concerns, intentions as well as his adopted and proclaimed main policies. The emphasis on paying attention to the experts’ findings of demographic policies is among the article’s objects of interests.