The terrestrial net primary production(NPP)and its spatio-temporal pattern in Qing-hai-Xizang Plateau during1982-1999were studied based on an ecological process model,using remote sensing data(NOAA-AVHRR),historical temperature,precipitation and solar radiation data,along with vegetation and soil texture information.As a result,a total mean annual NPP in the Plateau was0.21PgC(1Pg=10 15 g),occupying about 12.43%of China's total annual NPP.The NPP decreased from southeastern to northwestern part;this was coupled with the changes in precipitation and temperature.In the past18years,the terrestrial NPP in the Plateau increased from0.19PgC·a -1 in1982to0.24PgC·a -1 in1999,with an annual average increasing rate of about 1%.Regions with a significant increase in NPP appeared in southeastern Qinghai,Xining district,partial southwestern Qinghai,and eastern and partial southern Xizang.Monthly mean NPP for all months but not that for October and December showed an increasing trend through the past18years for most vegetation types.