The purpose of this study is to analyze the difference between school life adaptation and class cohesion according to the experience of school group training activities in elementary school students. This study used 350 students in the 5th and 6th graders of 4 schools in Seoul and Gyeonggi-do, and the data were analyzed by independent sample T-test, one-way ANOVA and post-test. First, 6th grade students were more likely to adapt to schoolmates than the 5th grade, and the class atmosphere, mutual trust, unity, and communication were also higher. On the other hand, there was no gender difference in school life adaptation and class cohesion. Second, elementary school students differed in their adaptation to the homeroom teacher, school friends, school study, and school rules according to the number of participation, the degree of participation, and satisfaction with participation in youth training activities. Third, there were differences in the class atmosphere, mutual trust, morale, unity, and communication among elementary school students according to the number of participation in youth training activities, degree of participation, and satisfaction of participation. Based on the above research results, this study suggested implications for the invigoration of youth training activities in school groups.