A common way of transferring ownership rights is the transfer resulting from the execution of mortgage documents, which is mostly forced and takes place without the owner's will. According to the mortgage documents, the debtor is usually made a pledge so that in case of non-fulfillment of obligations, the creditor can collect his claim from the mortgaged place based on this document. However, in some cases, the implementation of mortgage documents is challenging; such as when the property subject of the mortgage deed is among government property; In such a way that forced transfer is associated with difficulties or makes it completely impossible in practice. Due to the fact that in most countries, legal entities of public law can also become obliges of mortgage documents like private individuals, this challenge can be seen in many countries. In Iran's legal system, the mortgage execution documents for the property of some government agencies is associated with many ambiguous. Considering this issue, the current article has studied the most important ambiguous and challenges in this field and its findings indicate: the legal system that governs the execution of mortgage documents regarding property belonging to government institutions, according to the nature of the property (public or government), the type of actions (sovereignty or management) and the legal nature of the affiliated institution. (in terms of being a government institution, public non-governmental organization or a government company), it is different. Also, the implementation of mortgage documents regarding government institutions faces many legal and non-legal challenges.