Abstract: This study investigated into the course of formation and the main expressions of the differences in calligraphy between boy students and girl students. 540 students were chosen randomly from primary schools and middle schools,60 students (30 boys and 30 girls)in each grade from the first grade of primary school to the third grade of junior high school.They were asked to transcribe a short article with about 400 characters,540 transcriptions were obtained.Then 40 experienced teachers were chosen to judge the sex of the transcribers of each sheet,after forming each judgement they were asked to choose the evidences from a questionnaire on which they had formed the judgement.By using the signal-testing method,the researcher analyzed the accuracy of the judgement on the sex of the transcribers from each grade and revealed the age phase and the characteristics of the formation of the sex difference.The results showed:1.The formation of sex difference in calligraphy is a gradual course.There was no evident of sex difference in the lower grades. The sex difference did not appear strictly until the middle and higher grades.There were two accelerative phases in the course of the formation of sex difference.One was between the second and third grade,the other between the fifth and sixth grade. 2.The judgement to the sex of lower grades was less accurate because the judgers mistook the calligraphy of girls for that of boys.This showed that at the initial stage of handwriting,either the handwriting from boy students or that from the girl students expressed the same characteristics (male characteristics).The handwriting from the girl students did not form femal characteristics until the middle and higher grades. 3.There were five kinds of sex differences in the calligraphy between boy and girl students,which were the size of the characters,the dynamic degree,the vigorous degree,the neat degree and the angular degree.

Key words: calligraphy, sex difference, development