This study explored the gender difference in the children's self-development stage through sandplay. The subjects of investigation were in 16 children in the 5th grade in an elementary school in H-gun, Gangwon province: 2 groups of male children and 2 groups of female children. Each group composing of 4 children conducted an individual and group sandplay once a week for 70 minutes per each section and a total of 12 times, and the results were analyzed and counted. This study explored the gender difference based on Neumann's self-development five-stage theory through the individual and group sandplay. The findings of study were as follows: First, there was a difference in children's self-development stage shown in the individual or group sandplay according to the gender. Significantly, female children proceeded with the self-development stage more rapidly compared to the male children. Second, there was a difference of the contents that children showed in individual or group sandplay according to gender. Compared to the male children who expressed their struggle in a direct way, female children showed their struggle in an indirect way, which indicated that different gender showed the different ways of expressing sandplay. Consequently, it was found that children's self-development stage showed a difference to the gender in an individual or group sandplay and the contents of expressing sandplay showed a gender difference.