Preschoolers' understanding of moral, social-conventional, and personal domains was examined with 4- and 5-year-old children. Children evaluated moral, social- conventional, and personal events on six criteria - non-permissibility, seriousness, rule independence, personal choice, generalizability and locus of control, and also provided the justification for their judgment. On all criteria, 4-year-old children distinguished the events from three domains and 5-year-old children only distinguished personal events from either moral or social-conventional events. However, they made clear distinctions among three domains in terms of justifications of their judgments. Most children judged that parents should make decisions about moral, social-conventional, and personal events, but only some 5-year-old children thought children should make decisions about personal events.