The purpose of this study was to analyze the effect of school sports club activities on sportsmanship in middle school students. In order to achieve the goal of this research, 23,085 middle school students from 16 cities and provinces were sampled by using a convenience sampling method. The instrument used for this study was a questionnaire. The results of confirmatory factor analysis and index values of good of fit were rated as good. The data were analyzed through one way ANOVA and paird samples t-test using SPSS for Windows ver. 17.0. The results were as follows. First, there was a significant difference observed in all sub factors for sportsmanship(utmost effort, respect for teammates, respect for opponents, respect for judgment, acknowledging results) from all gender, grades, and class types respectively. Second, participation of school sports club activities on the part of middle school students had created a significant effect on their recognition of the sub factors for sportsmanship and as a result, all cohorts have displayed their enhanced awareness on the value of sportsmanship.