A method and a system for implementing time division duplex configuration of a secondary serving cell are provided. A primary base station receives time division duplex TDD configuration information of a secondary serving cell and an identity of the secondary serving cell from a secondary base station, where the TDD configuration information of the secondary serving cell is allocated by the secondary base station to the secondary serving cell. The primary base station sends the TDD configuration information of the secondary serving cell and the identity of the secondary serving cell to a terminal, so that the terminal determines an uplink-downlink subframe allocation of the secondary serving cell according to the TDD configuration information.