Net primary productivity (NPP) plays a critical role in forest carbon cycle and mitigation of climate change.China's evergreen broad-leaved forest is the main part of the worlds.By studying on the spatial-temporal characteristics of vegetation net primary productivity,it will have important significance to understand the growth condition of vegetation and CO_2 fixation ability in this region.The NPP data rooted in the Resources and Environment Science Data Center,Chinese Academy of Sciences.Based on kernel density estimation,membership function and other research software and methods,the NPP data were utilized to analyze the spatial-temporal characteristics of vegetation net primary productivity in subtropical evergreen broad-leaved forest from 2001 to 2010.The results showed that NPP in subtropical evergreen broad-leaved forest regions had no significant change.The NPP fastened on 300-400 gC·m~(-2)·a~(-1) and 700-1 000 gC·m~(-2)·a~(-1),and it presented the fluctuation changes in study region.Its annual mean was fluctuated between 600 and 700 gC·m~(-2)·a~(-1).There had a gradually decreasing trend of NPP from southeast to northwest in subtropical humid region,while the same trend occurred from west to east in subtropical semi-humid region.In addition,the variation coefficient of NPP was higher in west than east in the subtropical humid region,but higher in north than south in the subtropical semi-humid region.Through NPP and its variation coefficient,this paper obtained the spatial distribution of NPP membership degree,and based on the membership degree,it showed the increasing trend from the southeast coast to the inland.According above results,the article concluded that there had the greatest carbon sequestration,higher resisting disturbance capacity and low ecosystem risk in southeastern,but the opposite results in southwestern in subtropical evergreen broad-leaved forest region.