By using the transfer matrix method and finite difference time domain (FDTD) method, the propagation characteristics of artificial media based low-pass spatial filters were numerically simulated and analyzed. Two schemes were presented, and the method controlling the cutoff wave-vector of the spatial filters was obtained. Numerical calculations show that spatial filtering utilizing the indefinite metamaterial or low effective index photonic crystal processes near filed components and is inherent compact. It consists of multilayer of thin slabs, which are only a few wavelengths thick. The spatial filters based on the artificially media is significant in the high-power laser, which can decrease the spaces occupied by the conventional spatial filters.