A method, a user equipment, and a base station for transmitting channel state information (CSI) are disclosed. First, a scheduling grant command is sent by a base station. A CSI location label is obtained according to information of a resource occupied by the scheduling grant command and information of a resource occupied by a data channel that is indicated by the scheduling grant command. CSI of a carrier corresponding to the CSI location label is sent to the base station through the data channel. The CSI location label may be obtained through the scheduling grant command and the CSI of the carrier corresponding to the CSI location label may be sent or received without changing a length of an aperiodic CSI request field.