The purpose of this study is to explore the facilitators, barriers, and support factors experienced by Korean elementary school teachers when they integrate physical activity into their classes. The movement integration class dealt in this study means an educational activity in which the teacher intentionally integrates students’ physical activity in subject classes. Data were analyzed by employing a socio-ecological model(McLeroy et al.,1988). The facilitators of MI were characterized by teachers' personal beliefs about the value of physical activity, support & positive interaction with people around, improvement of school environment & support for educational activities, and educational programs linked with local community. As for the barriers to MI, insufficient teaching & learning knowledge, uncooperative people, temporal/spatial constraints & authoritative school climate, and national curriculum that requires a large amount of learning were derived. Support factors were activity-based teacher education, participation in teacher learning communities, systematic MI data construction & research environment, and pre-service teacher education on movement integration. Based on the research results, it was suggested that holistic socio-ecological measures surrounding teachers such as systematic training, accumulation of teaching & learning materials, activation of the teacher-learning community, and application in the national curriculum are necessary to support the movement integration practice of elementary school teachers.