Comparetive study of conditions to bring action of intervention in Iran’s law and United States Federal Rules of Civil Procedure

Intervention is one of the ancillary suits that should have the same origin or related to the original action so that the court can consider them altogether. According to 133 article of civil procedure the court is responsible to deal with the both claims simultaneously, only if the result of the main claim is dependent on the result of the intervention. In case that the main claim is not related to intervention, it is not necessary for the court to deal with them together. To be the beneficiary of the subordinate intervention may be in the form of possible interest or subordinate interest. On the basis that the intervener has a possible or subordinate interest in intervening the claim, the condition and proceeding of intervention would be different. This article is allocated to describe action. Basic of article is Iran’s law, as well as comparative study with of American’s federal civil procedure is conducted.