A user data management system of an electronic device includes a version database, a reading module, a version obtaining module, a change listing module, an adjusting module, and a saving module. The version database stores version change history for user data. The reading module reads the current user data from a source. The version obtaining module obtains the current version of the current user data, and obtains the latest version of user data from the version database. The change listing module retrieves changes between the current version and the latest version from the version database. The adjusting module applies the changes to the current user data and adjusts the current version of the current user data to the latest version. The saving module saves the current user data to the source.