This research-work examines the issue of the invalidity of the arbitration agreement in accordance with the provisions of the Omani law and in compared with Egyptian and Jordanian law, by studying the concept of the arbitration agreement. And identify its nullity censes and specialized legal ways of its so as to determine its results effects of its invalidity. This study aims to illuminate the value of arbitration agreement and its benefits to the parties involved, and the censes leading to its invalidity, the resulting effects, and the extent of the authority of court to settle the dispute concerned. The present research has concluded that the legislature of the terms of the law had shown clearly the arbitration agreement, its provision. And reasons underlying its invalidity, and articulated them in a manner that safeguard interests of both parties under the request of annulment (if and only if reasons prevail). This work ends up with a list of conclusions to reduce the effects of invalidity.