In wireless communication system, coverage area, transmission quality, signal strength are affected by shadowing, wireless interference, white Gaussian noise etc. This problems can be avoided by deploying more number of eNBs in geographical area, but it will increase deployment cost. In this paper a cost efficient Relay Station (RS) deployment using cost based RS placement (CRP) approach is proposed. After deploying the RSs, average received power by users are also calculated in the paper. The five parameters such as Transmission Signal Strength index (TSSI), RS placement Price index (RPPI), Area covered for service with population (ACS-P) and without population (ACS) and interference index (II) are calculated for deployment of RSs. The simulation results shows that CRP approach is a cost efficient approach. © 2016 IEEE.