Abstract: The large-scale migration in China has an important impact on the mental health of the rural children.The previous studies have only focused on the left behind children and migrant children,while ignoring the return phenomenon which is common for rural migrant children because of the current household registration system and education policies.The vast majority of migrant children will eventually be forced to become the returning children.Based on the survey data of 137 rural boarding schools in five counties of Hebei and Sichuan in 2015,this paper empirically examined the effect of Reflux on rural children's mental health.We find that reflux experience indeed has a significant negative impact on the mental health of rural children,which increases the risk of depression and lowers the self-esteem and resilience level.In contrast,the children who have short-term migrant experience will face a higher risk of depression once they returned.The returning children's self-esteem and resilience over time will be improved,but the risk of depression cannot be naturally released.Simultaneously,the mechanism analysis shows that the "double exclusion" from the urban and rural is an important reason for the deterioration of the mental health of rural children.

Key words: rural children, mental health, household registration system, urban education policies