With the rapid progress in wireless communication, adaptive or reconfigurable antenna are required to meet the changing in environmental conditions to achieve the highest performance of wireless communication. Therefore, reconfigurable antennas like frequency switchable antennas, pattern reconfigurable antennas, or polarization switchable antennas have attract many attentions these years. A frequency switchable antenna can avoid frequency deviation, or change its frequency band to the desired communication system. A pattern reconfigurable antenna can change its radiation pattern to be omnidirectional or to be end-fire according to the applications, or steer the high directive radiation pattern to the target. A polarization switchable antenna can change its polarization of wave to vertical polarization, horizontal polarization, right-handed circular polarization, or left-handed circular polarization. The advantage of this type of antenna is that it can eliminate multipath fading, or double the system capacity through a frequency reuse. In the literature, there are many polarization reconfigurable antennas have been proposed. In order to realize the antenna using printed circuit board, most of the antenna structure are based on microstrip antenna, whose antenna gain is relatively low. In this paper, a novel polarization switchable antenna based on substrate integrated waveguide is presented. The polarization of the proposed design can be switched between right-handed circular polarization and left-handed circular polarization. The switching of different polarizations can be achieved by employing the PIN diodes and changing the ON/OFF state of it. The proposed design is also measured and simulated to validate the proposed concept. The radiation characteristic of the proposed design is not sensitive to the size of the ground plane, also, the compact and single port design makes it more suitable for array configuration.