The primary objectives of this study are as follows: to examine (1) the relationship between children`s playfulness and creativity, (2) the relationship of subordinate factors of playfulness and creativity (3) the difference in playfulness and creativity according to sex and sibling relationship. The questions formulated for this purpose are as follows: 1. Are there any differences in playfulness in children according to individual characteristics ( sex and sibling relationship )? 2. Are there any differences in creativity in children according to individual characteristics ( sex and sibling relationship )? 3. What is the relationship between children`s playfulness and creativity? The subjects for this study were 98 children (54 boys and 44 girls) enrolled in classes for five-year olds in D kindergarten, Kangnam-Gu, Seoul. A translated version of Children`s Playfulness Scale by Barnett was used for the evaluation of playfulness, and MCAT-C (Multidimensional Cognitive Abilities Test for Children) was used for the measurement of creativity. Data were analyzed using Pearson`s correlation and stepwise multiple regression to look for the relationship between playfulness and creativity, t-test for sex differences, and F-test for sibling relationship. The results of this study are as follows First, for the total score in children`s playfulness, there were no significant differences according to the sex. Boys, however, received higher scores than girls in a playfulness subordinate factor of physical spontaneity For sibling relations, the eldest scored higher than the youngest or the only child in most subordinate factors of playfulness except in social spontaneity. Second, there were no sex difference in children`s creativity. However, there was a significant difference between siblings in the total scores of creativity and creativity measured through language. Specifically, the differences were found between the eldest and only child on the one side and the youngest child on the other side. Third, the relationships between the total scores and subordinate factors of playfulness and creativity in children were shown to be positively correlated. The most influencing subordinate factor in creativity was language.