Abstract: Based on open style interview with individual subjects and Giddens’ theory of structuration，and from the perspective of selfinitiative of migrant workers，this paper analyzes the relationship between the social security system under dual social structure and the protection action of migrant workers，with special focus on migrant workers’ response to the solidified social structure. Through analyzing the interview materials of individual subject，the authors find that dual social structure imposes restrictions on the action of migrant construction workers，by way of prohibiting and forcing their actions. On the other hand，migrant workers in cities display individual initiative in obtaining，using and recreating resources，opportunities and rules. In this way，the protection action of migrant workers has a great influence on both themselves and the systems，which to a certain extent brings changes to the structure.

Key words: dualistic society, social security, migrant workers of construction, migrant workers in cities