Legislative power is one of the main pillars of the Iranian legal system in the Constitution. So, holding open session in the Parliament is one of the important measures to protect the rights and public freedoms, to knowledge of the current affairs and to monitor the performance of the representatives. Meanwhile, if the holding open session in the Parliament endangers national security will certainly be influenced the country. Therefore, with outlined anticipation in Article 69 of the constitution, has provided to the President, one of the ministers, or ten representatives that to proposed holding closed session in Parliament. If the proposal approved, decisions in closed session is valid only with attendance of the total members of the Guardian Council to reach the approval of three-fourths number of the representatives. After the emergency condition disappeared, Reports and resolutions of the closed session should be published to the public. This article is to be analyzed the different aspects of this topic.