The first constitutional movement in the Islamic world occurred in the Ottoman Empire in 1876 AD; and thirty years later, in 1906 the Iranian Constitutional Revolution took place. As expected, these revolutions brought about a great transformation in both countries, having their own characteristics, differences and similarities. The present article will concentrate on the scale of power and authority of the Sultan in the first Ottoman Constitution comparing with that of the Shah's in the Iranian Constitution. Considering the detail of the authorities, the article will analyze the privileges given to shahs and sultans in the two constitutions. The article argues that the scale of authorities of sultan was very vast in a way that there were not much obstacles or limitation in forming of Abdul-Hamid's despotism. But the authority of the shah in the Iranian constitution was much limited.