Abstract: Orthogonal Frequency Division Multiplexing (OFDM) based Cognitive Radio (CR) Licensed users have to be deactivated to avoid interference. In this study, new pilot design method for OFDM based CR system has been proposed. The new optimization problem is formulated to remove the complexity of the existing method. Hybrid of bacterial foraging optimization and binary particle swarm optimization has been proposed to solve the optimization problem. Here, the comparison with the existing method, simulation results obtained by proposed method have been shown.