Abstract: By using the annual net primary productivity (NPP) data from 2000-2006 MOD17A3 dataset and the GIS technique, the spatiotemporal characteristics of grassland NPP in western Jilin Province were studied, with the related affecting factors analyzed. During the past seven years, the mean grassland NPP in this province was 232.14 g C·m^-2·a^-1, and the grassland area with a NPP of 200-300 g C·m^-2·a^-1 accounted for 59.47% of the total. 77.60% of the grassland had an increasing NPP, and the grassland area with a remarkable increase of NPP accounted or 15.0% of the total. Water condition was the main cntrolling factor for grass growth, and residential points had far more effects than roads, especially within 2 km from grassland, on the NPP.

Key words: Cicadulina bipunctella, Life table parameters, Host plants