Abstract: In this paper, strain measuring system based on chirped gratings and edge linear filtering demodulation technology is presented. In the system,the probe works with the wavelength difference of two fiber Bragg gratings as sensing information. This can eliminate the temperature influence on measuring result, and enhance the sensitivity and resolution doubly.Demodulation method adopts chirped grating and long period grating edge linear filtering technology. The system whose measuring range is 0～500με,is feasible in theory. The system can be used in monitoring marine platform, skyscraper,largescale structure and concrete dam.