Provided is a data federation system for a sociality storage service in cloud computing, the data federation system including an instance management unit to collect instance information from a cloud system for integrating cloud storage services provided to individuals, a service authentication unit to authenticate a state of the cloud storage services using the collected instance information, a storage synchronization unit to integrate cloud storages to collect data of the authenticated cloud storage services, and an index management unit to organize the collected data based on a state value of at least one of a file and a folder in the integrated cloud storage.