Automatic Voltage Regulator (AVR) is an important local system for synchronous generators used for electric power generation, to keep constant rated voltage value and control reactive power supplied to or received from the power system. For this purpose, providing the optimality of AVR system must be handled as a more important issue in terms of power quality and system security and reliability as well. In this paper, the heuristic optimization methods like Particle Swarm Optimization (PSO) Algorithm and Global Neighborhood Algorithm (GNA) are used comparatively so as to tune PID controller parameters of AVR system. The AVR loop is modeled from its transfer function. The optimization performances of the chosen algorithms are compared with each other by using transient response analysis.