A communicating method for an antenna array communication system, a user equipment and a base station are provided. The communicating method includes the following steps. A plurality of beams which are formed by a plurality of antennas is transmitted by a base station, and some of the beams is selected by a user equipment. A beam set of the selected beams for the user equipment is configured by the base station. A pre-coding information is fed back to the base station according to the configured beam set by the user equipment.