A user apparatus in a radio communication system including a base station and the user apparatus, including: a reception unit configured to receive a plurality of predetermined signals transmitted from the base station using a plurality of beams; and a transmission unit configured to transmit a preamble using a plurality of resources corresponding to the plurality of beams, wherein the reception unit receives, from the base station, system information including information of the plurality of resources corresponding to the plurality of beams, and the transmission unit obtains the information of the plurality of resources from the system information.