This paper presents the application of ND controller for SO, emission control process using Particle Swam Optimization PSO) algorithm. To minimize the impacts of SO, it must be removed from flue gas. Zeiglar-Nichols based PID (ZN-PID) controller is developed for SD= emission control process using MATLAB/SIMULINK platform. Based on the tuning parameters of ZN-PID controller, optimi-zation of ND controller parameters are obtained based on PSO algorithm. Performance of the PSO based PID controller is analysed and compared with Ziegler-Nichols PID controller (ZN-PID) and IMC controller in terms of time domain performance measures such as settling time and rise time (t, and t) and error indices (LSE„ IAE, ITAE). The simulation results proved that the PSO-PID controller provides most consistent performance as compared to the conventional controllers.