The purpose of this study was to identify differences in the aggressive behaviors of students with developmental disabilities as perceived by special education teachers depending on the school level in order to identify effective intervention strategies for managing the aggressive behavior of students with developmental disabilities in elementary, middle & high school. To achieve the research purpose, data from 355 people were collected using an online survey. As a result first, in terms of the urgency of intervention and coping experience related to aggressive behavior, both elementary, and middle and high school special education teachers recognized that intervention was most urgent for physical aggressive behavior; furthermore, it was discovered that, middle and high school special education teachers had more coping experience than elementary school special education teachers. Second, in terms of the degree of application and effectiveness of aggressive behavior intervention, it was generally recognized that middle and high school special education teachers applied the intervention more frequently than elementary school teachers; however, there was no significant difference in effectiveness with in both groups. Third, the level of psychological exhaustion experienced by elementary school teachers was perceived to be higher than that of middle and high school special education teachers; furthermore, the need for intervention-related support was also perceived higher by elementary school special education teachers. Based on the above research results, effective methods for intervention in aggressive behavior of students with developmental disabilities were discussed and suggested at each school level.