Idiom is an interesting phenomenon in languages. Understanding the expressions of idioms is essensial to gain succesful communication. One of the most interesting medium of learning idiom is using a song. This research is conducted on the basis of idiomatic expressions in the album lyrics of Justin Bieber purpose. This study focuses on three objectives of the study, they are; to analyze what types of idiomatic expressions in the album lyrics of Justin Bieber purpose, to analyze the interpretation of the purposes from the idiomatic expressions used in the album lyrics of Justin Bieber purpose, to explain the contribution of idiomatic expression in the album lyrics of Justin Bieber purpose to teaching idiom. This research used content analysis of descriptive qualitative. To collect the data, the researcher used documentation of the album lyrics of Justin Bieber purpose to gain the first and the second research problem, then used students’ worksheet to obtain the third research problem. Method of analyzing data used in this research is content analysis. The result of the study showed that idiomatic expressions used by Justin Bieber in the album lyrics purpose are 25 idiomatic expressions. Types of idiomatic expressions which frequently used in the album lyrics of Justin Bieber purpose is prepositional verb (V+Prep). The purposes from idiomatic expressions used in the album lyrics of Justin Bieber purpose are slightly different from the literal meaning of idiomatic. The researcher only found 1 idiomatic expression that have differences both in meaning and purpose, that is run out of time. The contributions of idiomatic expressions in the album lyrics of Justin Biebers’ purpose in teaching idiom are developing new method of learning, composing varied material and building joyful learning atmosphere.