In order to improve farmland productivity, the temporal and spatial features of farmland productivity were analyzed in the Sanjiang Plain from 2000 to 2005 based on the MOD17A3 data of NASA EOS/MODIS(TERRA). The results showed that the average net primary productivity (NPP) of dry farmland and paddy farmland from 2000 to 2005 were 348.06 g/(m2· a) and 339.90 g/(m2·a), respectively. Annual NPP of both dry farmland and paddy farmland were on descending trend from 2000 to 2005. The decline rate of dry farmland was 7.2%, and the decline rate of paddy farmland was 9.9%. The analysis shows that climatic change has some influences on the change trend of farmland productivity; meanwhile, the aggravation of effects on land-use by human activities has resulted in the decline of farmland productivity. The precipitation distribution has significant effect on the spatial distribution of farmland NPP, the correlation coefficient between the NPP spatial distribution of dry farmland and paddy farmland and the precipitation distribution are 0.177 and 0.156, respectively.