Qazvin became very significant after the formation of the Safavid dynasty and it developed and glorified during the reign of Shah Tahmasb. This city became the gathering and living place for those who came to it when it was announced as the capital. The political role of this city gave commericial and religious significance to this city. During this period, a number of mosques and monuments were built in this city. However, as the capital was transferred to Isfahan, Qazvin lost its place and this populated city underwent a number of political and social vissistudes, to investigate the urban spread and developments of this city demands a new study on account of its ethnic and religious diversity. In the present brief study the transfer of various tribes and religious groups and the officials and also their consequences in the urban anatomy of the city are considered.