Ⅰ. Problems of the study The purpose of this study was to investigate the effects of cooperative learning on the academic achievement of the elementary students\' different learning abilities and their self-esteem. The specific questions set up for this investigation were as follows: 1. Are there any differences in academic achievement of different learning abilities for the experimental group trained by Jigsaw I technique? 2. Are there any differences in self-esteem for the experimental group trained by Jigsaw I technique? Ⅱ. Methods and Procedures For this study, the subjects sampled were 72 children from 5th grade elementary schools in Pusan. The experimental group consisted of 36(Jigsaw I trained group) and the control group consisted of 36(traditional group). It took 10 weeks to train Jigsaw I of cooperative learning. The learning material unit is 『OUR COUNTRY’S ECONOMIC LIFE』in the social studies textbook for the 5th grade. The instrument utilized in this study was the Self-Esteem Inventory(SEI; Coopersmith, 1967). For statistical analysis, t-test was applied by using the SPSS computer program. Ⅲ. Results The results from this study were as follows; First, academic achievement scores in social materials of the group trained through Jigsaw I technique were higher than those of the traditional learning group. Second, academic achievement scores in social materials with high, middle, low class in learning abilities of the group trained through Jigsaw I technique were higher respectively than those of the traditional learning group. Especially, the middle class in learning abilities of the group trained through Jigsaw I technique showed the most significantly improved academic achievement in social materials compared with those of middle class learning abilities of the traditional learning group. Third, the self-esteem score of the group trained through Jigsaw I technique was higher than that of the traditional learning group. Fourth, the self-esteem scores with middle, low class in different levels of the group trained through Jigsaw I technique were higher respectively than those of the traditional learning group. Especially, the low class in different levels of the group trained through Jigsaw I technique showed the most significantly improved self-esteem score compared with that of low class of the traditional learning group.