Impleader is one of the ancillary suits that parties to the dispute according to it can claim against third party. Although Iran’s legislator in the laws related to this claim has not specified conditions of mentioned claim, according to article 17 of civil law, it should be related or have the same origin with main claim, so that the court can hear and decide them altogether. The result of being related or having the same origin of impleader with main claim is that relief of impeder can be different from relief of main claim. American’s Federal Rules of Civil Procedure has provided different legal mechanisms for aggregation of claims that three of them are similar to regulations of impleader in Iran’s law which are as follow: joinder (rules of 19 and 20), impleader (rule 14), cross claim (rule 13). The basis of study is Iran’s law, even though comparative study with American’s Federal Rules of Civil Procedure will be done as well.