Abstract: In recent years， the issue of migrant peasant workers has attracted a lot of attention at home and abroad. Taking the migrant workers in a shantytown in Shanghai as the study subjects， this paper discusses with the conception of “social construction” the mechanisms for their identity formation after their entry into the city. The author contends that the household registration system (the Hukou system) is the macrolevel context for the formation and upholding of the identity of “migrant worker.” Meanwhile， this collective identity is being construed and symbolized through daily interactions， and it is getting recognized widely， as migrant workers live with the native residents in the same community. In the paper， the author also proposes the conception of “migrant space.” With country people migrating into the city， this living space clustered with migrant workers is becoming a unique urban space which functions as a spatial symbol for their identity.

Key words: identity formation, migrant peasant workers, migrant space, symbolization