Due to the importance of the documents, especially the commands, which nowadays are among the most important sources of studying in the historical researches, the written documents have special credit and importance as the primary sources and a kind of these documents are kings’ decrees, which are very important in more accurate studying of political, cultural, economic and social events, because they contain many contents and tips about historical, art, political, geographical, social, legal, financial and military issues. In the writing of decrees, the view of the government's highest decision-making body have been considered and theirs contents are largely devoid of sympathy or hatred. Each of theirs sheets depends on an actual time and a specific event, and turn light on the dark sides which historians have forgotten them because of inaccessibility to the main sources, such as the mechanism and the reasons of the removal and installation of important government officials adoption or repeal of state regulations and etc In this research the Qajar’s decrees from the beginning of their rule until the Nasseri period have been studied. The decrees of this period made of various components such as beginning (matla’), passion description (sharh e eshtiagh), conclusion (Hosn e Khetam) and several additions that will be described. Then the statue of these decrees in the Qajar history will be studied and we will show how a document reread would be useful in turning light on a vague historical point.