Islamic banking conduct intermediary function and social function. Social function of Islamic banking was characterized by the zakat function and qardhul hasan. The aim of the paper is to describe the implementation of Corporate Social Responsibility in Islamic banking in Indonesia. Dimensions of CSR covers Modes of CSR Activities, CSR Collaborative Agencies, CSR Beneficiaries. This paper uses qualitative method especially the descriptive qualitative method. This paper analyzes the annual report in 2016 of Islamic Banking in Indonesia with content analysis method. Islamic banking in Indonesia were reflected by the Bank Muamalat Indonesia and Bank Syariah Mandiri which have the similarity of size, business scale and age. The result of this paper can describe the implementation of Corporate Social Responsibility of Bank Muamalat Indonesia and Bank Syariah Mandiri through social function and all dimensions of Corporate Social Responsibility. Corporate Social Responsibility in this paper covers Modes of CSR Activities, CSR Collaborative Agencies, CSR Beneficiaries.