Abstract: Based on data from the National Forest Inventory from 1973 to 2008, the net production and mean net primary productivity of China's forests were estimated by various forest types and climatic zones. The results showed that, over the last 40 years, the total net production and mean net primary productivity of China's forest was increasing. The total net production increased from 803.359×106 t·a-1(1973 to 1976) to 1 478.425×106 t·a-1(2004 to 2008), with an increase of 84.03%. The mean net primary productivity increased from 7.302 t·hm-2·a-1(1973 to 1976) to 9.502 t·hm-2·a-1 (2004 to 2008), with an increase of 30.13%. The subtropical mixed evergreen-deciduous broadleaved forest, Betula and Populus forest, temperate typical deciduous broadleaved forest and subtropical evergreen broadleaved forest made a greater contribution to the net production of China's forest. The tropical rainforest and monsoon forest, subtropical mixed evergreen-deciduous broadleaved forest and subtropical evergreen broadleaved forest had higher mean net primary productivity, while that of Pinus tabulaeformis forest and P. massoniana forest were lower. Among different climatic zones, the net production of forest vegetation reduced in fluctuations in the tropics, while it increased in all the other three climatic zones. From 1973 to 2008, the relations of the mean net primary productivity in different climatic zones are as follows: tropical (18.625 t·hm-2·a-1) > cold and temperate (9.610 t·hm-2·a-1) > subtropical (8.499 t·hm-2·a-1) > warm temperate (7.800 t·hm-2·a-1).