Islamic economy in Indonesia is in continuous development qualitatively and quantitatively. There are products of Islamic financial institutions which innovatively developed. However, there are findings which stated that the Islamic financial institutions in Indonesia still not in full compliance with the Shariah, especially in terms of fulfilling the justice experienced by Islamic bank’s mudarabah contract customers. The injustice is on the nisbah or ratio between the capital owner and the capital manager. There ara model or proposal to how to determine the profit sharing ratio, however, there is still none of them which dwelling on the idea of justice in profit sharing ratio. This research, using an explorative and qualitative approach contributes to the philosophical basis in determining the just profit sharing ratio. The reason for the research is since justice is one of the Islamic economy pillars in Islamic economy paradigm. By this research, it is hoped that the future practice of profit sharing ratio will be just for the actors of the Muḍārabah contract.