This study was to investigate the effect of teacher reactivity enhancement program on problematic behavior of infants of inclusive class. For this, 30 children of inclusive classes of two nursery schools located in G city in Geollamnam-do were selected as experimental group and comparative group. The results produced by performing teacher education for five tirnes during five weeks are as follows: First, it was appeared that teacher reactivity enhancement program decreased problematic behavior of general infants in inclusive class. Second, it was appeared that teacher reactivity enhancement program decreased problematic behavior of infants with developmental delay in inclusive class