Based on the birefringence effect of one-dimensional subwavelength metallic grating and equivalent medium theory (EMT) is generalize to a two-dimensional subwavelength structure to analyze a two-dimensional metallic rectangular gratings in order to realize the control of polarized state from incidnet linear polarization to output arbitrary polarized state transformation. Finite difference time domain (FDTD) algorithm is performed to analyze properties of polarization and transmittance of the light. Simulation results show that the full Poincaré sphere coverage could be obtained theoretically by space angle modulation, and the high transmittance can be achieved as well.