The motivation of this thesis is to characterize the polarization state and spatial coherence of the diffraction-limited visible synchrotron radiation (SR) beam at Stanford Synchrotron Radiation Light Source (SSRL or SPEAR3). Polarization and spatial coherence are two important properties of SR beam, the reason lies in three aspects. Firstly, specific polarized SR can be used for detect the structure property of some material, so it is necessary to know the beam polarization before using them. Secondly, the theoretic SR field model (Schwinger's Equations) can be verified in the visible regime. Thirdly, beam polarization research is at the foundation for beam coherence research, particular for measuring the degree of spatial coherence using a double slit interferometer. Show Partial Abstract