Based on Yeh's (2004) "Ecological Systems Model of Creativity Development", this study investigated the effects that age, the use of emotion regulation strategies, temperament, and exposure to creative drama instruction have on the development of creativity among preschool children. Participants were 116 4- to 6-year-old preschool children. This study categorized the emotion regulation strategies used by preschool children and developed a creativity test which includes the measurement of "usefulness", an indicator of creativity that has, until now, been ignored. The main findings are that (a) 6-year-olds outperform 4- and 5- year-olds in terms of creativity; (b) emotion regulation strategies as well as a positive temperament have positive effects on children's creativity; (c) creative drama instruction contributes to children's creativity; and (d) age group, emotion regulation strategies, temperament, and creative drama instruction can collectively predict children's creativity. (Contains 4 tables.)