One kind of polarization splitter using two-dimensional photonic crystals is shown in this study. Both finite-difference time-domain simulations and equi-frequency contour plots in the first Brillouin zone are used to demonstrate how such a polarization splitter work. Basically, these phenomena are resulted from the different dispersion properties of two-dimensional photonic crystals for TE and TM polarization. And thus such a structure can be employed as polarization splitters for integrated optical and microwave components