The LPJDGVM (LundPotsdamJena Dynamic Global Vegetation Model), which is a processbased model, is used to simulate the vegetation distribution and estimate the interannual variation of net primary production (NPP), heterotrophic respiration (Rh) and net ecosystem production (NEP)in China from 1981 to 1998. It is shown that there are six main plant functional types (PFTs) besides the desert,that is tropical broadleaved evergreen tree, temperate broadleaved evergreen tree, temperate broadleaved summergreen tree, boreal needleleaved evergreen tree, boreal needleleaved summergreen tree and C3 perennial grass. In China, the total NPP varies between 2.91 Gt·a-1(C) (1982) and 3.37 Gt·a-1(C) (1990), increases by 0.025 Gt (C) average per year and has an increasing trend of 0.96%. The total Rh varies between 2.59 Gt·a-1(C) (1986) and 319 Gt·a-1(C)(1998), grows by 1.05% per year and by 0.025 Gt(C) per year. The linear trend of NPP and Rh for C3 perennial grass is more remarkable than those for other PFTs. The simulation of NEP is reasonable when the fire is brought in the model. Annual total NEP varies between -0.06 Gt·a-1(C)(1998)and 0.34 Gt·a-1(C)(1992). It is demonstrated that the terrestrial ecosystem is carbon sink in China. The above results are similar to those simulated by other models.