This research describes the promotion strategy of Jogja Audio School in order to increase the number of customers through social media in 2016. Researcher chose JAS as object because it is the company that active promoting their services using social media. The content which is uploaded by JAS is unique and well packaged. These excellences make JAS become an audio school that competing with the competitor from outside Yogyakarta. The purpose of this research is to explore how the promotion strategy that used by JAS in order to increase the number of customers through social media. The type of this research is the case study of qualitative description. The technique of data analysis that researcher used is the Miles and Huberman model. The data came from interviewing and documentation. The result of this research shows that JAS’s promotion strategy, is using seven steps in the planning, using many media promotion in the implementation, and do the evaluation every month.