Abstract: Based on a representative questionnaire survey among migrant workers in Shanghai, and employing acculturation and identity formation theories, this article examines the determinant factors which affect migrant workers’ social identity. The research finds out that the huge ruralurban gap has endowed migrant workers an ambiguous identity in which they physically live in city but mentally are identified with the country, and more importantly, their institutional welfares are confined to the country. The ambiguity of their social identity is attributed to both the institutional hurdle of the hukou (household registration) system and constrained agency caused by scare resources. At a more concrete level, this research suggests that five important factors have contributed to the formation of their social identity: proficiency in local language, willingness to make friends with local people (but not other migrant workers from other provinces), income level compared to peers, perceived social acceptance, and access to social insurances. Being positive for all five factors will make a migrant worker more identified with the city rather his/her rural origin. Meanwhile, migrant workers’ demographic features such as education, migrating time and occupation also influence their social identities. Overall, the authors suggest that public policies should be helpful in terms of the transformation of migrant workers’ social identity, particularly their perception changing from “being an outsider” to “being a local”.

Key words: social identity, acculturation, identity, migrant worker, social integration