The purpose of this thesis is to examine the experiences of the Arab Republic of Egypt, the Republic of France and the Sultanate of Oman in the field of reviewing the constitutionality of the laws, which is important in ensuring that the constitution is intact and not violated by other legislations, which calls for the existence of a specific mechanism is the presence of a particular authority for this task. The study examined the constitutionality of the laws in terms of historical developmeni and the mechanism of their application in Egypt and France by means of comparison, analysis and devising with a view to identifying the best ways to propose their application in the Sultanate of Oman to control the conformity of laws and regulations with the basic law in light of Article 70 Of the Omani basic systein of 1996. . The topic of this study was divided into an introductory chapter in addition to three chapters. The introductory chapter was devoted to the discussion of the origin and types of constitutional supervision. The first chapter deals with the examination of the competent authorities to review the constitutionality of the laws and the methods of constitutional appeal, in view of the difference of jurisdictions since the Supreme Constitutional Court is the competent constitutional control in Egypt, however In France, the French Constitutional Council has jurisdiction over reviewing the constitutionality, which of course means different methods of appeal as well, The second chapter discusses the challenges of unconstitutionality and the validity of the rulings issued in the constitutional cases and their implications, which are similar in nature to most countries that have the constitutional review system, In the third chapter, we discussed the status of monitoring the constitutionality of laws in the Sultanate of Oman, entitled the prospects of controlling the constitutionality of laws in the Sultanate of Oman, Through examining the type of review exercised in the Sultanate of Oman and its competent in the absence of the application of the text of Article 70 of the Omani basic system, And what is the future vision in terms of the formation of the Constitutional Court and procedures of the constitutional case in the of Oman through existing laws and proposed laws to be issued. The researcher reached several conclusions, the most important of which is the absence of an effective regulatory system on the review on the constitutionality of laws and regulations with the basic system in Oman, and suggested that the establishment of a constitutional court be expedited under a special section of the Omani basic system.