The present disclosure relates to a method for reporting channel state information, a user equipment, and a base station. A channel state information measurement resource is determined by a UE according to an aperiodic CSI trigger signaling, so that a base station transmits a CSI-RS only when the UE needs to report the aperiodic CSI. Compared with transmitting a periodic CSI-RS by an existing base station, unnecessary transmitting of the CSI-RS is reduced, and energy of the base station such as an eNB is saved; and reducing the CSI-RS transmission may reduce resources occupied by the CSI-RS, thereby improving the spectrum efficiency of the system. In addition, reducing unnecessary CSI-RS transmission allows the interference in other cells by the base station being reduced; finally, CSI measurement resources are reserved only when the CSI needs to be fed back, the cost occupied by the CSI measurement resources is reduced.