Net primary productivity (NPP) of grassland plays an important role in terrestrial ecosystems, and its spatial heterogeneous traits have significant influence upon regional carbon cycle, grazing capacity, soil erosion, and ecosystem safety assessment. How topography, one of significant environmental factors, affects grassland productivity is not well addressed in the remote sensing of grassland ecosystems. This paper selected a protected meadow of the National Natural Reserve of Huihe wetland, used USGS EOS-MODIS/Terra NDVI data and GLCF DEM data, and adopted spatial analysis function of ARCGIS to analyze the NPP distribution pattern form 2000 to 2012 in Hulunbuir meadow based on the ground spectrum biomass model, topographical controlling factors, and yearly precipitation classification. The results showed that the ground spectrum biomass model can be used to assess meadow productivity, and the most suitable model is y =15.968e^3.5434x (Sig=0.000) for predicting Hulunbuir meadow productivity in regional scale (where y and x represent productivity and NDVI, respectively). Simulated results confirmed that topography had a remarkable impact on meadow productivity distribution pattern. Consequently, among three topographical factors of altitude, slope and aspect, altitude gave rise to the most significant changes, the effect of the slope was intermediate, and the aspect played a minimal effect. Firstly, under the conditions of the slope of 0-2 degrees and aspect of NE, NPP increased 0.478 g/m² per meter rising of elevation in normal yearly precipitation level; 0.414 g/m² in lower yearly precipitation level; 0.482 g/m² in moderate yearly precipitation level; and 0.525 g/m² in higher yearly precipitation level, respectively. Secondly, under the conditions of altitude of 760-780 m and aspect of NE, the meadow productivity decreased 0.142 g/m² per degree increase of slope in the normal yearly precipitation level, and decreased 0.161 g/m² in the lower yearly precipitation level, 0.135 g/m² in the moderate yearly precipitation level, 0.133 g/m² in the higher yearly precipitation level, respectively. Thirdly, under the conditions of the altitude of 760-780 m and the slope of 0-2 degrees, the highest NPP (184.6 g/m²) occurred on the N aspect and the lowest NPP (173.3 g/m²) on the W aspect, respectively. The NPP was lower on the SW aspect in the lower yearly precipitation level and on the W aspect in the moderate yearly precipitation level. By contrast, lower NPP occupied on the SE aspect in the higher yearly precipitation level. According to NPP distribution area, the topographical factors had higher (lower) effect on NPP of the meadow than soil heterogeneity (grassland type) on spatial scale. The trend of this effect did not vary across years with various NPP but differed in effect degree, being higher in the years with intermediate NPP.