This study focuses on the development and application of the trunk-kit (teaching material kit) for experiments visualizing the phase change of water. This kit allows the teachers who are weak in science to demonstrate the experiments for pupils in the classroom easily. The trunk is a reused suitcase and contains the teaching materials for the 4 experiments as follows: (1)Regelation, (2)Observing of Snow crystals growth,(3) Observing of Ice crystals, (4)Freezing of the super cooling water. These experiments will attract the schoolchildren and stimulate their curiosity. The kit is compact and easy to move, so it is always available to any teacher who wants to perform the experiments.