In this paper, a simple beam splitter (PBS) with two-dimensional photonic crystals is proposed. According to different dispersive and propagating characters of TE mode wave and TM mode wave in three kinds of photonic crystals, the structure can split one light beam of TEM mode into two beams with TE mode and TM mode, respectively. Compared with other general PBS, this structure is simple and flexible, meanwhile, a larger separating angle of 1800 for splitting is obtained, therefore, this features of the proposed PBS make it a promising candidate in optical communications applications.