Two dimensional periodic arrays of dipole and patch elements can be used as frequency selective surfaces (FSS) for polarization or frequency filtering at microwave frequencies. Numerous papers dealing rigorously with the study of FSS in the frequency domain have been published. All those methods directly give the characteristic of the FSS frequency by frequency. Computation time becomes important if these structures have to be studied over a very large bandwidth. Analysis methods in the time domain, followed by Fourier transform, have the advantage of directly given characteristics versus frequency. In this paper we introduce a new way for modeling and analysis of different FSS structures in the time domain using the 3D-transmission line matrix (TLM) method. All numerical results predicted by the TLM method are compared with experimental results, and good agreements are obtained.