This study was conducted in order to investigate the effects of middle school students’ physical activity pleasure on inner motives of PE class, interest and immersion. Subjects of the study were middle school students, and for data collection 660 samples in total were collected through a convenience sampling method and 641 copies of data were employed for final analysis. Collected data was analyzed through frequency analysis, correlation analysis and multiple regression analysis using SPSS 18.0 and the following results were obtained: First, if all the factors of physical activity pleasure are high, interest and efforts which are inner motives are high, and if physical activity pleasure of creativity, cooperation mind, interest, and self-confidence is high, competence which is a inner motive is high. And while creativity and cooperation mind of physical activity pleasure increase tension which is an inner motive, interest of physical activity pleasure reduces the tension factor which is an inner motive. Second, if all the factors of physical activity pleasure are high, a sense of achievement which is an interest factor, and physical and mental health maintenance is high, and if physical activity pleasure of creativity, cooperation mind, self-confidence is high, cultivation of sociability which is an interest factor is high, and if physical activity pleasure of creativity and cooperation mind is high, easiness of the class which is an interest factor increases and if physical activity pleasure of creativity, cooperation mind, health maintenance and aesthetic experience is high, freedom of the class which is an interest factor increases. In addition, if every factor of physical activity pleasure is high, immersion in content of PE class which is immersion factor is high, and if physical activity pleasure of creativity, cooperation mind, health maintenance and aesthetic experience is high, challenge spirit and control ability which are immersion factors are high and class behavior and awareness match well with each other, and if physical activity pleasure of creativity, interest, self-confidence, health maintenance and aesthetic experience is high, autotelic experience which is an immersion factor increases. Third, if all the factors of inner motives of middle school students are high, cultivation of sociality and easiness of the class are high which are interest factors of PE class, and if inner motives of competence, interest, and efforts are high, a sense of achievement which is an interest factor, and physical and mental health maintenance increases, and if inner motives of interest and tension are high, freedom of the class which is an interest factor of PE class increases. Besides, if all the factors of the inner motive are high, immersion in content of PE class which is its immersion factor, challenge spirit, control ability, class behavior and awareness match well, and if inner motives of competence, interest, and efforts are high, autotelic experience increases, which is an immersion factor of PE class.