The author studied how the fifth graders could understand music through body movement as expression. This was done by analyzing the data of the music learning process of "Stick Dance" which contained both rhythm exercise and improvisational dance performance. The analysis was carried out with the emphasis on the perception of musical elements and the imaginative reaction. The graders could develop their musical understanding in the following way. The perception of five meter, and the imaginative reaction to it. Then, the interaction of the perception and the reaction to other musical elements.