Even if Internet has been used very much, there is no method of music aptitude test for children. We develop the music aptitude test in the internet to make music aptitude test easily. We test children for music aptitude early. We provide children the learning and instruction environment. This research makes children improve the ability of music. We develop the music aptitude test system for children in the WWW for children to use it. This system is expected to be a great help for children to test music aptitude easily. This system establish a well-understood and maintenance through this system for replacing the data files of their children in a effective way.