The number of internal migrant children in China has reached 35.8 million by the end of 2010. Previous studies revealed inconsistent findings regarding the mental health status of rural-to-urban migrant adolescents, as well as the impact of peer, teacher and parental support on the mental health of Chinese adolescent migrants.

Using a comparative approach, this study attempted to compare the mental health status between migrant and urban-born adolescents and to clarify the specific roles of different sources of social support in the mental health of migrant and urban adolescents.

A cross-sectional survey using a cluster convenience sampling strategy was performed in Beijing, China. A structured questionnaire was filled out by 368 rural-to-urban migrant adolescents and 325 urban-born adolescents.

A significant difference was found only for positive affect (PA) but not for negative affect (NA) between the two groups, favouring the urban-born adolescents. Social support from all the three sources were all predictive of PA among rural-to-urban migrant adolescents, while only peer support contributed to PA among urban-born adolescents. Unexpectedly, teachers’ support contributed to an increase in NA among urban-born adolescents.

The findings contribute to understanding of the mental health status of migrant adolescents in China and the differential impact of the various sources of social support on migrant and urban-born adolescents. Also the findings may inform the development of mental health services and programmes that can potentially benefit a large number of internal migrant adolescents in China.