Background: Big data refers to a huge set of data so that collecting, analyzing and managing data could be beyond the ability of PCs over a given period of time.  Big data as an enormous source of information can affect the various dimensions of social and moral life of human beings. Along with the development of big data and technologies based on big data, the social, political, economic and general aspects of contemporary world information ecosystem have undergone fundamental changes that have led to emerging and various ethical issues and challenges. One of the most important ethical challenges is the impact of big data on the moral agency of the human agents in the information society.
 Conclusion: In this article, by referring to technical resources, the concept of moral agency is introduced and the big data implications on moral agency are investigated. The development of big data and its related technologies, the following quadruple components are effected strongly: 1) free will and choice possibility, 2) knowledge of the results of action, 3) the causal relationship between action and its results, and 4) the ability of ethical agents. However, these components are introduced in traditional ethical systems as the most important conditions for the realization of moral action and agency. Next, the impact of big data on the four components of moral agency be explained at three levels: 1) weakening traditional concepts, 2) changing traditional concepts, and 3) developing new concepts. Accordingly, it is concluded that Big Data changes, evolves and develops the four essential conditions of moral agency in traditional ethical systems.