The intention of the study was to improve the musical instruction of a grade three class. The theory of multi-intellingences(MI) and the method of collaborative action research were the major bases to reach the intention. Firstly, the group of the action research explored the implications of MI in musical instruction. Second, they tried to construct practicable strategies for musical instruction based on the implications of MI proposed by themselves. During the processes of construction, they constantly evaluated their students' responses to modify and reconstruct more proper strategies for musical instruction. Seven practicable strategies for musical instruction were constructed finally. These strategies could not only promote students' abilities of music, but also enhance their interests to music. That is, the musical instruction of the class was really improved.