One of the important events of Iranian Constitutional movement was the participation of Bakhtiari tribal Khans’ force against despotic fans and their effective support of constitutionalists and their cooperation in conquering Tehran in July 1909. This activity on the part of Bakhtiari Khans due to this fact that this political movement was born out of the needs of city community and was not related to the tribal community, has surprised the political and historical analysts. This paper, therefore, has attempted to analyze the structural features of tribal community and to evaluate their military capacity produced within this structure. It was due to this military power that tribes and nomads could dominate the Iranian states. This paper will analyze the action of Bakhtiari Khans in this respect.