The teaching material about the state change from the water vapor to the water drop caused by the shift of air temperature is presented. The ping-pong balls and tiles as a model of water vapor/drop are put into the transparent box and sheet which denote the conceptual model to understand the characteristic of saturated water vapor. When the transparent pillar shifts to the left, same ping-pong balls and tiles drop down with sound and bouncing motion on the desk. The trial lesson by using this model is conducted in the public junior high school. Many students answered that this lesson was enjoyed and that students of over 60 % could choose right answers. The rate was higher than that in the previous report. The results show this teaching material is one of the effective teaching material about the state change from the water vapor to the water drop caused by the shift of air temperature.
