NDVI trends for overlapping time period of 2000-2004 years were compared between GIMMS-NDVI, Spot-VGT and Terra-MODIS series of satellite images. The maximal values of spectral index for observed vegetation periods were noted for each pixel of Bolshezemelskaja tundra image (covered near 270 th km2) as a basis for proceedings. Greater similarity was observed for average values (2000-2004) between Spot-VGT and Terra-MODIS data (r = 0.895, p < 0.05). The spatial-temporary decorrelation was observed for other comparable pairs. Differences in the width of the spectral bands of satellite sensors (RED and NIR), spatial resolution of images, calculation algorithms or the influence of unaccounted weather conditions were main predictors of decorrelation.