The purpose of this study was to inspect how much influence Praise Program based on Activity has on elementary school students' self-concept and sociability development. To achieve this purpose, the following research questions were set up. The subjects were 54 students of 5th grade from 2 classes(27 students for each experimental and controlled group) at S elementary school in Daejeon. For the experimental group, total 10 sessions of Praise Program based on Activity were applied while no special treatment was done to the controlled group. At the end of the test, post experiment test was performed both for the experimental and controlled groups. Some of the remarkable results were as follows; Praise Program based on Activity resulted in the positive improvement of elementary school students' self-concept. In the sub-fields of self-concept such as general self-concept, academic self-concept, significant others self-concept, emotional self-concept, the statistics results showed meaningful differences. Praise Program based on Activity resulted in the positive improvement of elementary school children's sociability developments. According to the study, in sub-fields of sociability as the field of diligence, responsibility, cooperation, the law-abiding spirit and independence, the results showed meaningful differences. In conclusion, Praise Program based on Activity is shown to be very effective in improving self-concept and sociability development of elementary school students. Accordingly, it is expected that the program can be helpful to students to develop self-concept and sociability in school life.