Abstract: The purpose of present study is to investigate the development of the concept of gender constancy in preschoolers aged of 3, 4, 5 and 6 with modified method of interview. The results showed that the concept of gender constancy developed in terms of 3 continuous levels: Level 1. The notion of gender identity was acquired in 3~4 years old; Followed by level 2 gender stability, that is, children (around 4 and 5 years old) got to know that gender could not be changed with time passing by, and, finally level 3. the notion of gender consistency developed speedily in 5、6 years old. More than a half of sample of 6-olds has already acquired the concept of gender constancy. In the clarified condition the rate of achievement for passing the tasks in children was increased greatly. There is no difference of the development between self gender constancy and others one in preschoolers, except 3-olds

Key words: preschooler, gender identity, gender constancy