The present disclosure relates to a method for reporting channel state information, a terminal, and a base station. A resource for an aperiodic channel state information reference signal (CSI-RS) is determined by the terminal according to an information for triggering an aperiodic channel state information (CSI) report sent by the base station, wherein the information for triggering the aperiodic CSI report indicates the resource for the aperiodic CSI-RS, and the aperiodic CSI report derived according to the aperiodic CSI-RS on the resource for the aperiodic CSI-RS is sent by the terminal to the base station. The base station transmits a CSI-RS only when the terminal needs to report the aperiodic CSI.