Due to the economic imbalances and the restriction of household registration system, the number of floating population in China has increased year by year since 1980s. In recent years there is a tendency for the floating people to settle down, which causes more and more migrant children to follow their parents to live in cities and receive education here. Since most of the migrant family can’t receive the same public service as local people, their living status, and especially their children’s mental health, is becoming hot issues. Questionnaire has been designed by using The Piers-Harris Children's Self-consciousness Scale. One primary school and two Junior high schools of Nanjing were chosen. All students were investigated, and 453 migrated children were selected after data arrangement. Then contingency analysis, analysis of variance and logistic regression were used to analyze impacts on self-consciousness of migrant children. There are significant differences in various schools and families. In general, the family condition of migrant children in Hongyuan Junior high school is the best, and that in Shazhou Junior high school is the worst. Variables such as father’s education, birth place, gender, grade and school can influence children’s self-consciousness. But school plays a more important role than family in the development of children’s self-consciousness. The results show that both family-related and school related-factors can affect migrant children’s self-consciousness. A close relationship with family members can reduce the occurrence of low self-consciousness. High academic achievement is related to high self-consciousness. And teachers’ care can influence migrant children’s self-consciousness.