The present study examined the development of self-understanding in the preschool and grade school years, as revealed by children's self-descriptions and self-evaluations. Thirty-two 5 year olds, 37 second graders and 35 fourth graders were interviewed about their self-definition, self-evaluation and interests. Children's answers were classified according to the modified Damon & Hart (1988) category scheme and the main results were as follows. First, with age, self-descriptions about physical features became less common, whereas descriptions about activities and personality traits increased in frequency. Second, many children in all age groups gave some descriptions about harmonious relationships, and the varied use of specialty words for descriptions about ability, competence and diligence increased in number with age. Third, while many preschoolers described only positive and likable aspects of themselves, most school age children described both positive and negative aspects of self. In fact, many 4th graders described only their bad aspects.