Abstract: This paper investigates an efficient design procedure integrating the genetic algorithm (GA) with the finite difference time domain (FDTD) for the fast optimal design of smart antenna array (SAA). The FDTD is used to analyze SAA with mutual coupling. Then, on the basis of signal to noise ratio (SNR), the genetic algorithm is applied to optimization of weighting element and structure of SAA simultaneously. The mixed programming for MATLAB and Fortran program is used to optimize linear equally spaced array and smart antenna circular array. Finally, the effectiveness of the analysis is evaluated by experimental antenna arrays.