An RCU (remote control unit), an antenna apparatus, an antenna electrical tilting method and an antenna system. The RCU includes a reading device and a driver. The reading device is configured to read, from a memory inside the antenna apparatus, when the antenna apparatus is communicatively connected with the RCU, antenna information of an antenna controlled by the antenna apparatus and configuration data corresponding to the antenna. The antenna information includes the antenna serial number and the antenna model of the antenna. The driver is configured to control the antenna apparatus to adjust an electrical down-tilt angle of the antenna in accordance with the configuration data.