Abstract: NOAA/AVHRR reflectance and normalized difference vegetation index (NDVI) data have been widely used in meteorological and hydrological fields.Because the bi-directional reflectance distribution of surface and the scatter and absorption effects of atmosphere, even though the surface keeps unchanged, the reflectance obtained by satellites can vary greatly.After cloud-removing and degradation-correcting processing, atmospheric corrections are carried out to NOAA/AVHRR visible and near-inf rared reflectance and NDVI data using the 6S model, and then bi-directional reflectance corrections are carried out.The atmospheric correction makes the visible reflectanc decrease by 3.34 (reflectance unit), the near infrared reflectance increase by 3.43 (reflectance unit), and increases the NDVI increase by 0.22, equaling to 78.2 percent, 15.9 percent and 35.5 percent of theirown respectively.The bi-directional reflectance correction does not affect the amount of NDVI distinctively, but can remove the irregular variances of the reflectance and NDVI.After corrections, the reflectance and NDVI can reflect the phenological effect of deciduous forests (the land cover of the surface target).At last, based on the error analysis, the sensitivities of correction errors to the errors of correction parameters are given, and the results show that the solar and satellite zenith angles are the most sensitive parameters.