The aim of this study is to investigate the administration of full-time inclusive elementary classrooms and the support needs of teachers. To achieve the goal of this study, in-depth interviews were conducted with five general education teachers who have experience of full-time inclusive classroom. The findings of this study regarding the first research question of the administration of full-time inclusive classrooms are as follows. First, the placement of students with disabilities depended solely on parents and teachers were assigned by lot. Second, IEP for students with disabilities were developed by only special education teachers without collaboration with homeroom teachers or not developed. In case of IEP developed, IEP were not appropriately implemented. Third, during instructional time, classroom teachers often ignored students with disabilities or assistant teachers were charged of students with disabilities. Forth, classroom teachers could not take into account ‘disabilities’ of students with disabilities regarding classroom management. The findings of this study related to second research question, the supports needs for elementary edcucation teachers of full-time inclusive classroom are as follows; first, systematic support system including reducing the number of students per classroom and restructure of physical environment should be established. Second, instructional materials, educational program and consulting for classroom teachers should be provided. Third, disability understanding program should be provided for teachers, students, parents and administrators differently. Fourth, special education teachers should collaborate with teachers for full-time inclusive classroom.