All musical works are utilizing many characteristics of sounds such as high and low, long and short, loud and soft, and fast and slow. Due to the level of musical development, exploring the characteristics of sound is very important for lower grade elementary school children to develop their sense of hearing and to formulate concepts about the constituent of music. Therefore, they need materials which help them to explore several characteristics of sounds in musical works. In this study, I have developed multimedia materials which enable children to study the characteristics through interacting with computer and to control the learning order for themselves. In order to develop the materials, I investigated the level musical growth of lower grade elementary school children, the use of multimedia in music instruction, the present situation of music educational multimedia title, and the basic theory for designing multimedia materials. I selected the topic, teaching objects and learning contents by analyang contents concerning the characteristics of sounds in the textbook titled Pleasant Life for first and second grades and the music textbook for third grade. I designed a flowchart and storyboard and used Multimedia Toolbook 3.0 as a multimedia authoring tool. The material developed here allow children to select their learning order by using hipertext and to participate in learning spontaneously through interacting with computer. I included the graphics which were concerned with learning contents in a set scene, made texts simple, included video and audio materials designed for exploring sounds. `Multimedia Materials for Exploring Sounds` wlll be helpful, when teaching and exploring of sounds. And this materials can be used as referential materials for developing musical multimedia as assistant teaching materials.