This research examined the rise and the activities of teacher's organizations in terms of persistence and change of colonial educational experience during the period from 1945 to 1950. It will serve to understand the formative process of the characteristics of present Korean education. Small teachers associations were risen right after liberation. It was possible due to the inertia power of the colonial educational experience of people generating, operating, participating in, and resisting to former teacher's organizations. These were integrated into Korean Teachers Union(朝鮮敎育者協會) in Feb. 1946. It inherited the flow of socialistic movement in order to establish Korean teachers organizations in 1930s. And it meant explicit rise of new teacher's organization which got out of bureaucratic and colonial nature of colonial period but had strong ideological nature. Korean Educational Association(朝鮮敎育聯合會) was established in NoⅤ. 1947 to the purpose of positively eliminating Korean Teachers Union in educational field. The leading groups were educational bureaucrats and principals. And One of them had participated in Japanese teacher's organization in colonial period. Korean Educational Association maintained bureaucratic, colonial, and modern nature of Japanese teacher's organization in colonial period. That was possible by intentional strategy for elimination and selection which was performed in conflicts and competition among groups.