Disclosed is a block toy for music education which recognizes combined melody blocks so as to replay sounds in order having the same pitch as the melody blocks, thereby playing a melody. The corresponding melody block is lit up to display a playing melody block while playing a melody. It is possible to differentiate each melody block by detecting, with a mechanical switch, uneven patterns formed at the lower sides of melody blocks. Since music can be visually understood, the block toy can help the emotion and music education of children.