Abstract: Effect of positions of transmit antenna and stirrer, shape of stirrer on field distribution in a reverberation chamber is analyzed from simulation, experimental verification and theoretical analysis.Genetic algorithm is applied to optimize positions of transmit antenna and stirrer, shape of stirrer and the global in a reverberation chamber.The results show that, compared with optimizing the position of transmit antenna, the field uniform is much better and the comprehensive evaluation function F changes more intensively when optimizing the position and stirrer of stirrer, which shows that field distribution is more sensitive to stirrer than transmit antenna; the field uniform is best and the comprehensive evaluation function F changes the most intensively when optimizing the global of the chamber.The mechanism that key arrangement have an effect on field distribution is studied through theoretical analysis,the essence of chamber optimization is revealed.The results of simulation is identical with theoretical analysis.The results of simulation is verified.