The present study was to investigate children's self-evaluation of their past, present, and future, and to set the stages of developmental process based upon the results. The method employed was to ask children to give their preference or rejection of “younger age”,“actual age”, and “older age” with its reasons. The analysis of the data led us to set the following three stages of the developmental process in children. The first stage, in which children chose their actual age as the best for the main reasons that they had become aware of their development in various abilities together with a greater amount of experience. In the second stage, they chose their actual age as best, but not so positively as in the first stage, because they were enjoying their actual life. In the third stage, they viewed their actual age in the negative, the largest number choosing the older age as the best while the second largest choosing the younger age.