This study has paid attention to the methodological approach in curricula and music textbooks in Korea, USA, and Germany. Simple description of good posture and breath for singing appears in Korean textbooks. Also, American music curriculum and textbooks for general music education rarely mentioned how to practice children’s singing voice. Interestingly, in German’s textbooks, specific activities appear for developing children’s voice and it helps student understand how to sing systematically. This article has two results: First, to improve singing voice, student needs to learn good posture, breath, and vocalization all together. Second, it is a significant point for elementary school’s singing class that music textbooks have to provide practical ideas for voice training.