It is provided a method for providing complementary information for principal information in a system having a first presentation device for presenting the principal information and a second presentation device for presenting the complementary information. The method comprises the steps of receiving a piece of principal information to be presented on the first presentation device; determining control information of at least one piece of complementary information associated with the received piece of principal information, wherein, the control information comprises a start time point for each piece of complementary information indicating when to present the complementary information, and sending an instruction message to instruct the second device to present the at least one piece of complementary information associated with the received piece of principal information based on the start time point contained in the control information and time information carried in the received piece of principal information.