The conversion of faith happening to an individual is not an accident. On the other hand, it has been preceeded by the processes and conditions possibly learned. The decision taken by the individual changing faith (muallaf) is the most difficult part in his/her life since it can affect his/her life here and after. In this case, the faith is converted from non-Moslem into Moslem. After becoming a Moslem, the muallaf needs assisstance and guidance from his/her closest people or from an institution. Related to this need, in Yogyakarta, there is an institution guiding and accompanying the muallaf that is Muallaf Center Yogyakarta. Besides, there is also da’wah strategy in every institution to make their da’wah activities run well. Muallaf Center Institution Yogyakarta has management staffs and guided muallaf consisting of diverse Islamic organizations. This research aims to find out how the strategy of da’wah in Muallaf Center Institution Yogyakarta and to find out the Islamic organization mapping in Muallaf Center Institution Yogyakarta. This research used qualitative approach with inductive analysis technique through presentation of descriptive data forms. The data collection technique included observation, interview, and documentation. This research was conducted in Muallaf Center Institution Yogyakarta. The research result shows that Muallaf Center Institution Yogyakarta used three da’wah strategies those are gentle strategy, strategy using logic, and strategy using witness. The Islamic organization mapping in Muallaf Center Institution Yogyakarta is various since all organizations are included in Muallaf Center Institution Yogyakarta.