In this paper, we propose a new random access strategy for multi-channel cooperative relaying networks and provide detailed analyses about the performances of our scheme with/without considering the impact of interference caused by the introduction of Distributed Relay Stations (DRSs), besides, a new sharing scheme of sub-channels is presented. Our proposed scheme takes the different requirements of services into consideration, and exploits the cooperative relaying nature for multi-channel environments, e.g. Orthogonal Frequency Division Multiplexing Access (OFDMA). Due to differentiation of services and definition of special channels, those users with Real-Time (RT) request can reserve the access channels in advance, while others with Non-Real-Time (NRT) services can access to the Base Station (BS) or the nearest DRSs, which are deployed for cooperative relaying, through sharing those channels remained. Furthermore, for solving the interferences which caused by the sharing of sub-channels for NRT access, the Soft Frequency Reuse is introduced for the resource sharing scheme. The analyses and numerical results demonstrate that our scheme can achieve higher throughput, lower collision probability and lower access delay.