The method for calculating OLR (Outgoing Longwave Radiation) with FY-2C geostationary satellite data is described, including the establishment of the FY-2C OLR inverse model and the detailed procedures of calculating OLR by using the measurements in the FY-2C window and water vapor channels. The quality of FY-2C OLR products is discussed by comparing with NOAA OLR products nearly at the same time on the OLR isoline charts. The difference between the two products ranges from 0 to 20 W/m, with the maximum difference being 20 W/m. An example of FY-2C OLR products and application is also given.