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Based on temperature and precipitation data of the whole country from 2000 to 2015, the Thornthwaite Memorial model (TW) and Zhou-Zhang (ZGS) model were used to calculate the potential net primary productivity (NPP) and the actual net primary productivity, the data of landuse change slope method was combined to analyze the farmland ecosystem, forest ecosystem, grassland ecosystem net NPP, interannual fluctuation trend and spatial variation characteristics, and the correlation between the actual productivity and potential productivity was evaluated. The results showed that the spatial pattern and change trend of national NPP simulated by the above two methods were basically the same, and the overall correlation was very high, the determination coefficient R2 can reach 0.7707. For the correlation of all land vegetation ecosystems, from most significant to least significant was as follows: forest ecosystem, farmland ecosystem, grassland ecosystem; the spatial distribution of the net primary productivity of vegetation in China presented the spatial difference of “high in the south and low in the north”, which showed a gradual decline trend from southeast to northwest; in the past 16 years, both potential and actual productivity of vegetation in China showed a slow decrease trend, if no measures were taken, decreasing trend would be maintained. The research results provided a scientific basis for China to take compulsory measures to protect the ecosystem.