A method of synchronizing a first device capable of displaying video content and including the video content, and a second device capable of displaying E-book content associated with the video content and including the E-book content. The first device is connected to the second device according to a specific protocol. In response to a specific event for the video content or the E-book content occurring in one of the first and second devices, the device in which the specific event occurs generates event information about the specific event and transmits it to the other of the first and second devices, and performs the specific event according to the event information. Upon receiving the event information, the other of the first and second devices performs the specific event according to the received event information in synchronization with the device in which the specific event occurred, using synchronization information between the video content and the E-book content.