The purpose of this study is, in depth to understand elementary obese students that are participating in the physical education classes and their experiences and to clarify obesity students' perception of the body image, motor ability, and physical education classes. In order to achieve the purpose of this study, I selected 6 obesity research participants, grade 5 students at Gwang-ju B elementary school. In this study to collect data on participant observation and depth interview methods were used. For data analysis, I analyzed by 'inductive content analysis method' and on the basis of the analyzed and interpreted data, major results were drawn as follows: 1) depending on the level of obesity or physical activity-related individual past experience, obesity students have various perceptions about their body image and motor ability. 2) perception of obesity students to the physical education varies according to the individual experience participating in physical activity. And, obesity students prefer a competition activity and hate a health class. 3) the experience of success in physical education classes gives obesity students a positive intrinsic motivation and helps them more active participation. but, if the task presented inappropriate & difficult task for their skill level and physical fitness, the obesity students were participating more passively.