The purpose of this study was to make an action study of reflective simulated instruction in an effort
to facilitate the improvement of the teaching professionalism of preservice early childhood teachers and the
improvement of this researcher's own educational practice. It's specifically meant to develop reflective
simulated instruction and to research its process and outcome after teaching preservice early childhood
teachers using it during a semester. Reflective simulated instruction was conducted by this researcher and
68 early childhood education students who were in their third year at a college. The reflective journals of
this researcher and the preservice early childhood teachers, video clips of the instruction, interview data and
research daily were all gathered during the process of the reflective simulated instruction, and then an
inductive analysis was made. The first stage of the reflective stimulated instruction was planning, where an
instructional plan was mapped out after reflecting on existing simulated instruction and by modifying it.
The second was a stage of acting out, which consisted of preparing lesson plans, producing teaching aids
and materials, videotaping the instruction, evaluating/feedback, self-reflection, modification and re-instruction.
The third was a stage of observation, where the meaning of the experience of the preservice early
childhood teachers who attended the reflective simulated instruction was analyzed. The fourth was a stage
of reflection, where the reflective simulated instruction was modified and a new plan was prepared based
on the results of the instruction. As a result, it was possible for the reflective simulated instruction to
boost the reflective thinking of the preservice early childhood teachers and to exert a positive influence on
the improvement of their teaching professionalism.