The purpose of this study was to examine the relationships among infants' playfulness, musical attitude, and spontaneous music behaviors. The subjects for this study were 101 infants who were two-to-three years old and enrolled at 7 Child Care Center in Seoul and Kyonggi-do. In order to examine the infants' playfulness and musicality, Barnett's (1990) 'The questionnaires about playfulness', Bang's (2008) 'The questionnaires about musical attitude', and Hwang's (2008) 'The behavior styles and frequencies during spontaneous music play' were used. The results were: (1) There were significant differences in sub-factors of spontaneous music behaviors between two and three year olds. And there were significant differences between the sexes in sub-factors of musical attitude and spontaneous music behaviors. (2) A positive relationship was shown among playfulness, musical attitude, and spontaneous music behaviors. (3) Playfulness affected infants' musical attitude positively. (4) Playfulness affected infants' spontaneous music behaviors positively.