As China is experiencing an urban revolution with massive rural-to-urban migration, millions of children are profoundly affected by their parents' migration and their decision on family arrangement. With the discriminatory Hukou system and harsh living conditions in cities, the dilemma migrant parents face is whether they should bring children to cities or leave them behind. This decision determines the household, school and community environment children live in, which in turn shapes their wellbeing. With a unique strategy of comparing "left behind children" to "migrant children" and a gendered perspective, this paper examines how different family arrangements among migrants and consequent housing conditions and gender dynamics affect children's educational wellbeing. Our findings demonstrate the complex impact of family arrangement on children, which is conditioned on wage income and the gender of absent parent and the child. We find that children from less favorable socioeconomic backgrounds benefit more from moving to cities. Children living with both parents and those living with mother and grandparents tend to do better. While the effect of housing conditions is marginal, family arrangement has a gendered effect on children. Related policy recommendations are provided.