A physical channel communication method and apparatus for random access in a cellular communication system including a plurality of relay nodes and user equipments using the same system information is provided. The physical channel communication method for random access in a wireless communication system according to the present invention includes receiving, by at least two relay nodes connected to a base station, system information containing a Physical Random Access CHannel (PRACH) region allocation information for identifying user equipments attached to the relay nodes; receiving PRACHs for random accesses transmitted by the user equipments; and transmitting the PRACHs to the base station on relay node-specific resource regions according to the PRACH region allocation information.