By using vegetation type map, NDVI (normalized difference vegetation index) data sets, meteorological data and observed NPP data, the paper droved CASA (Carnegie-Ames-Stanford Approach) ecosystem model to estimate net primary productivity for terrestrial ecosystem in East Asia region (10-70°N，70-170°E). The results indicated that NPP tends to increase during 1982-1999, with an average increase of 0.08833PgC per year. The mean total NPP during 1982-199 is 14.24 PgC, making up 22.6%～23.9% of global NPP. Annual NPP change takes on a single peak curve. NPP reaches the peak value (2.98PgC) on August. 96.81% of the total NPP accumulates during the period of April to October in a year. On the average, spring, summer, autumn and winter NPP in the study area are 2.31 PgC，8.16 PgC，2.79 PgC and 1.10 PgC, comprising 16.20%，57.27%，19.58% and 7.73% of the total annual NPP, respectively. This paper divided NPP value of the study area into the low value zone (7.82-300gC·m-2), middle value zone (301-700 gC·m-2) and high value zone (>700 gC·m-2) and studied their spatial distribution characters.