Provided are a method and apparatus for sending uplink control information. The method comprises: a terminal receiving downlink control information (DCI) sent by a base station, wherein the DCI comprises at least one of the following: a related first control domain for indicating downlink scheduling, a second control domain for indicating that the terminal determines an HARQ-ACK feedback mode and a third control domain for indicating a PUCCH resource used by the terminal when the terminal determines to feed back an HARQ-ACK; the terminal determining related parameter information required when the terminal feeds back HARQ-ACK information according to the downlink control information, wherein the related parameter information comprises: the number of HARQ-ACK bits, a PUCCH format of the HARQ-ACK and the PUCCH resource corresponding to the PUCCH format; and the terminal sending the HARQ-ACK information to the base station. The present invention solves the problem of how a terminal determines a PUCCH format of sending an HARQ-ACK when the PUCCH format is newly introduced.