Dynamic monitoring of regional NPP (net primary productivity) has important significance for research on global change. The NPP of Xinjiang grassland from 2001 to 2010 was estimated using an improved light use efficiency model based on MODIS-NDVI,land use classification data and meteorological data. Spa-tial-temporal variation features of grassland NPP from 2001 to 2010 in Xinjiang were studied and analysed. The spatial distribution of NPP in Xinjiang grassland was constrained by the regional hydrothermal conditions. Grassland types were generally distributed as alpine and sub-alpine meadow, plain grassland,meadow, desert grassland, alpine and sub-alpine grassland from north to south. The grassland NPP reduced from 395 g C/ (m~2 · a) to near 0 g C/(m~2 · a) and 10-year average total NPP of Xinjiang grassland was 56. 47 Tg C. Compared with other grassland types,mean NPP of meadow was the highest (155. 29 g C/m~2 · a),while mean NPP of desert grassland was the lowest (57. 68 g C/m~2 · a). The overall level of mean NPP was meadow>al-pine and sub-alpine meadow>plain grassland>alpine and sub-alpine grassland>desert grassland. The overall level of grassland NPP in Xinjiang was rather low, where alpine and sub-alpine meadow, plain grassland and meadow belonged to lower productive ecosystems,and desert grassland,alpine and sub-alpine grassland belonged to the lowest productive ecosystems. On the main grasslands in Xinjiang, the NPP from June to August occupied 63. 17% of the whole year. The monthly NPP in different grasslands changed differently but all peaked in July. Compared with other types, NPP of alpine and sub-alpine meadow increased more quickly in the first seven months, while alpine and sub-alpine grassland were the slowest. The decrease of meadow NPP was quicker than those of other grassland types in the last five months,while desert grassland was the slowest. With the exception of meadow, the mean NPP of the other four grassland types showed a downward trend from 2001 to 2010 in Xinjiang. Total NPP of grassland in Xinjiang reached the maximum (60. 21 Tg C/a) in 2007, and dropped to the minimum (53. 41 Tg C/a) in 2006. During the past 10 years, the grassland NPP in Xinjiang showed a great annual fluctuation but with an overall reduction trend.