Abstract: The purpose of this study was to reveal preschool children’s understanding of the origins and controllability of dreams. 173 children aged 4, 5, 6 were interviewed and the results showed: (1) Preschool children understood the roles of experience, knowledge in the origins of dream as adults did, but it’s not available for preference. (2) Frequency of participants who realized dreamers’ unsatisfied desires could influence their dreams in 6-year-olds (about 43%) was larger than that of 4- to 5-year-olds (about 20%), and smaller than that of adults (about 73%). (3) Preschool children didn’t understand that dreaming could not be controlled; they didn’t realize dreaming was an unconscious process, and approximately 80% of them believed that individuals’ desires could control their dreams

Key words: understanding of dream, origins of dream, controllability of dream, preschool children