An information processing method and apparatus are disclosed in a multicarrier communications system. In the multicarrier communications system, a terminal is configured with a PCC and at least one SCC. A first base station in which the PCC is located transmits downlink data to the terminal by using a PDSCH on the PCC; and the first base station demodulates a PUCCH on the PCC by using a first format and a second format, to obtain feedback information sent by the terminal, where the first format is a PUCCH format used for a single serving cell, and the second format is a PUCCH format used for a plurality of serving cells. Therefore, a problem that downlink retransmission is continually performed because feedback information cannot be demodulated due to inconsistent PUCCH formats is resolved.