This study is aimed at improving of the ability to solve language problem and reducing of problem behavior with delayed language development children through music programs. This subject of this study is 7-9 years olds with delayed language development children. Research designs were analyzed as ABAB designs from a single case study. The programs consisted of a total of 16 sessions(first baseline-3 sessions, first music program-5 sessions, second baseline-3 sessions, second music program-5 sessions) and 30 minutes/1 session individually. The results of the study are as follows: First, The ability to solve language problem has been improved. Second, The ability to repetition nonsense syllable and number had been improved. Third, the ability to maintain the topic has improved. Finally, the ability to follow the third direction was improved. According to the results of the study, speech-rhythm music activities could be used as a tool for delayed language development children to improve their language skills with other ways than language. In particular, speech-rhythm music activities have provided the opportunity to actively express what happens in everyday life in their own words, and the structure of the rhythm can provide attention to the structure of time flow.