A group of reference calibration coefficients for CBERS-2's CCD data were provided by cross calibration method by using LANDSAT5 TM data.The validation for the cross calibration shows its feasibility.A method,which is based on 6S model and isochronous meteorological information on sensing time,was used in the atmospheric correction of CBERS-2's CCD four bands.Validation analysis was conducted by comparisons of corrected and uncorrected reflectance data including normalized difference vegetation index(NDVI).It finds that the corrected reflectance of CCD3 and CCD4 increases clearly and the NDVI of vegetation ascends while the NDVI of nonvegetation descends.