This study looked into the roots of Korean music education through researching the backgrounds and the processes of school music education in the U. S. military government period. This study examined the educational policies conducted by the U. S. military government, including the educational principles, systems and curricula. The conclusions found through the analysis of the \"Elementary Song Book\" published in August, 1946 are the following: First, it established the new educational principle, \"the welfare of mankind\", through the reformation of educational systems and the introduction of mandatory education focusing on democracy. In other words, it stressed the expansion and the equity of educational opportunities, the development of curricula and teaching-learning methods and the security of the educational independence. It emphasized the establishment and foundations of democratic education. Second, it eradicated the colonial education of Japanese imperialism, making new curricula systems and time allotments to foster democratic citizens of the new country. Third, it contained only western music, since it is not ruled by Korean own government but by the U. S. military in spite of its release from Japan. Finally, the textbook showed the music classes still employed the characteristics of \"sho-ka\" rather than music. The above principles and educational methods founded the roots of Korean music education of today.