Abstract : This thesis aims to study security rights in movable property by examining Article 9 of the United States’ Unified Commercial Code, UNCITRAL Model Law on Secured Transactions and the recently enacted laws on Secured Transactions of Egypt, Palestine and UAE. The Thesis addresses security rights, which is consider a property right, over movable assets. This security right secures the right of the creditor in the event of the debtor's default whereby if there are competing claims over the same encumbered asset the secured creditor enjoys priority in enforcing his right in the asset over unsecured creditors and other secured creditors with a security right that follow his security right in the order of priority . The Thesis addresses the security agreement as a security right may not be created without a security agreement, which must be signed by the debtor, except where the encumbered asset is in the possession of the secured creditor. The encumbered asset must be reasonably described in the security agreement so as to allow its identification. A security right is effective against the debtor and creditor as soon as a security agreement between them is concluded. However, for the effectiveness of the security right against third parties, one of the method specified for this purpose must be satisfied. This thesis addressed four methods for achieving effectiveness of a security right against third parties. These include the registration of a notice, possession, control and automatic effectiveness in the case of consumer goods. One of the important legal issues discussed in this thesis is the rules governing priority where there are multiple security rights of creditors over the same encumbered asset. Legislation on Secured Transactions include rules that address the order of priority where there are creditors with competing security rights. A creditor with a security right that was made effective against third parties through registration of a notice, or any of the other method of achieving effectiveness against third parties, has priority in enforcing his security right over other creditors who follow him in order in making their security right effective against third party. The general priority rule is "First in time, first in right".