The present invention discloses a method for transmitting channel state information, a user equipment, and a base station. The method includes: determining to-be-reported channel state information CSI, where the to-be-reported CSI includes at least one CSI report, and each CSI report of the at least one CSI report corresponds to one downlink carrier; and sending the to-be-reported CSI to a base station through a physical uplink channel. The user equipment includes a determining module and a sending module. The base station includes a receiving module, a first determining module, and a second determining module. According to the method, the user equipment, and the base station in the embodiments of the present invention, channel state information from different downlink carriers can be transmitted on a same subframe, and a performance requirement of the reported channel state information can be ensured, and power utilization efficiency can be improved.