The purpose of this study is to discuss the policies for supervision over preschool teachers to increase the expertise of day care teachers. The discussion on supervision is focused on the educational aspect of day cares. This study aims at searching for the direction of supervision in day cares, based on the results from the study on supervision over kindergarten teachers. The results of this study are as follows. First, the policies for supervision in day cares should be introduced at the national level. And the educational function of day cares should be reinforced. Second, the scope of supervision in day cares should be discussed and negotiated. Third, the attempt should be made to approach the proper, multilateral, and distinguished supervision. Fourth, the attempt to improve self-supervision in day cares should be made. Finally, self-supervision and peer supervision, which are appropriate for day cares, should be planned and carried out in day cares.