This study was conducted in order to survey intellectual disabled students’ behavioral characteristics related to physical education perceived by the teachers and the teachers’ instructional performance in physical education class inclusive intellectually disabled students, and to examine the relationship between the two factors. Accordingly, the subjects of this study were teachers in charge of integrated physical education class, and a total of 146 teachers were sampled through random sampling and data from surveying the teachers were used in analysis. The research tools used in this study were newly developed scales on intellectually disabled students’ inclusive physical education behavior and on inclusive physical education teachers’ instructional performance, and the contents, validity, and reliability of the questionnaire were verified. According to the results of this study, intellectually disabled students’ behavioral characteristics related to physical education were categorized into their general behavioral characteristics, and behavioral characteristics depending on the severity of disability. In addition, with regard to integrated physical education teachers’ instructional performance, their acceptance of disabled students’ needs was in a high correlation with their experience and training in integrated education, but their instructional adaptation, support to disabled students, and separate instruction were not significantly different among the teachers. These findings suggest that students with intellectual disability in integrated physical education class have a limitation in their participation in class activities due to their different behavioral characteristics but they showed high preference for physical education class, and that teachers need to be provide with continuous training in order to accept and cope with intellectually disabled students’ needs properly.