I have examined 20 different kinds of references of Kagok, Kasa and Shijo in the music textbooks ranging from the third grade of primary school to the first grade of high school(10th grade) which are used as educational materials for the current music study. Shijo is introduced in the listening part in the textbook of the 5th grade in primary school for the first time and Kagok and Kasa including Shijo in the textbook of the first grade of middle school(7th grade). In the first grade of high school Kagok, Kasa and Shijo are introduced in the listening part with the staff notation of Pyoung-Shijo as a song to be taught. Those textbooks with Kagok, Kasa and Shijo, include the origin, singers and listeners, categories and musical characteristics of the songs in the listening past with some explanations and comparative tables. And the melodic lines and rhythmic patterns of them are introduced partially in the staff notations and Chungganbo(Korean traditional score). I have examined the explanations of music of Kagok, Kasa and Shijo in the textbooks; the esthetics, origin, lyrics, tonal system, categories, performance style, and rhythmic pattern in detail. I also analyzed the Pyoung-Shijo of Seoul style with the staff notation; the key signature, pitch, tempo, vibrato, musical skill, rest and syllable arrangement.