The form of the Child Welfare Service changed drastically with the revision of the Child Welfare Act in 2012. In the Act, the section addressing day service for children changed, that is, after-school care for mild disordered children provides more diversified services. The purpose of this study was to clarify mothers' precess of understanding their developmental disordered children by semi-structured interview. The results indicated that mothers' needs and expectation to the service differed in accordance with psychological level of their understanding of their children. In addition, it was suggested that reconfirmation of the needs and expectation was effective for mothers who recognized the service negatively.