A high temperature reaction system includes a reaction tube including a heating space, a discharge unit, a cooling unit, a feeding unit and an observation and analysis unit. The discharge unit is disposed opposite to an inlet of the heating space and has a discharge space communicating the heating space, and an observation window and a discharge opening which communicate the discharge space. The cooling unit has a cooling space communicating the discharge opening. The feeding unit includes a carrier holding a sample, and a moving module for moving the carrier and the sample. The observation and analysis unit includes an image capture module and an analysis module for analyzing gas released by the sample.