A real-time solution concentration monitor based on Fabry-Perot interferometer is designed.The concentration variation measurement is realized by the F-P interferometer and optical fiber to transmit the image to the CCD.The relation between the variation of interference fringes of the F-P interferometer and the fluctuation of solution concentration is analyzed.The monitor system consists of He-Ne laser,optical fiber,planar F-P interferometer,arrayed CCD and PC is set up.Three different glycerin solution are used to verify the system design,and the experiment shows the system can provide a resolution on the order of 10-4 concentration variation.