Since the institution of government is important, different typifications of it have been offered by sociologists and political scientists.
The criteria that have been utilized are as follows: people"s participation in government (Aristotle), people"s participation and the existence or lack of laws (Montesquieu), the status of political institutions (Shills), the society"s dominant culture (Almond), the type of rulers (Badie), the numbers of political parties (Aron), etc.
In addition to this typification, there were some studies and arguments about these differences. Among scientists who have analyzed the causes of diversity among governments one can point to Aristotle, Montesquieu, Moor, de tocqueville, Rostow, Barbo, Almond and Lipset. In this typification, factors such as weather, historical circumstances, culture, economy, psychological characteristics and so on have been considered.
In this research the sociological foundations of political systems and their relation to some factors such as level of development and social indexes are surveyed.
The resuls have revealed the significant statisitical relation between the studied variables and type of social system.