Abstract:This paper studies the net primary production of ravine tropical rain forest in Xishuangbanna at an elevation of 2300m (N 25 24‘E 102 45‘ ). The estimated NPP(net primary production)of ravine tropical rain forest is 2298.0 g.m-2.a-1, of which 33.32% is stems,18.22% branches,29.56% leaves,14.84%roots,0.39 %flowers,1.26% fruits, and 2.40% leaf biomass grazed by insects.The NPP percentagesoftree-layer.shrub.herb and inter-layer are 88.42% , 3.74%, 4.44%and 3.39% respectively.