A novel planar antenna with quadri-polarization diversity, including a pair of orthogonal linear polarizations and a pair of orthogonal circular polarizations is presented in this paper. The antenna comprises two square patch resonators and a feeding network with 4 input ports. Antenna polarization diversity can be achieved by selecting different inputs, which can generates right-handed circular polarization, left-handed circular polarization, horizontal linear polarization and vertical linear polarization. The proposed design does not need PIN diodes and DC biasing circuits, which makes it suitable to be used in higher frequency applications where lump elements are difficult to be utilized. This novel antenna provides potential polarization diversity features for wireless local area networks and multiple-input multiple-output systems. Details of the antenna design are shown, and the measurement and simulation results are also provided to validate the proposed idea.