Abstract: A method and apparatus for synchronization of contents in a cloud service system for a mobile environment is provided. The synchronization method of a cloud service system includes uploading, at a device when data is changed, the changed data to a server, processing, at the server, the uploaded data, storing, at the server, the processed data along with a time change, transmitting, at the device, a synchronization request signal including a most recent server connection time at a predetermined time, downloading, at the device, a data log on data changed between the most recent server connection time and the current time, synchronizing, at the device, the data based on the data log, and updating the most recent server connection time.