This study investigated the differences, depending on the time of year, in preschool clean-up time used by teachers. It analyzes preschool teachers' narratives based on videos of clean-up time in June and October in a class of four year olds. The results were as follows: (1) The teachers in both June and October respect children's play. However, in October the teachers expect the children to clean up after themselves. (2) In June, teachers constantly emphasize the need to clean up to the children, but in October they don't need to mention it so often. (3) In June, teachers clean up first and then work together with the children, while in October they mainly leave this work to the children. (4) In June, teachers instruct directly and concretely, while in October teachers instruct indirectly and generally. (5) Because clean-up time becomes part of the daily routine, differences of practical knowledge between June and October occur. (6) The differences of practical knowledge depending on the time of year are related to the preschool curriculum, teaching plans and children's developmental changes.