Abstract:Carbon dioxide and its flux with water and heat exchanging was studied by means of the gradent observation and outline methods in near canopy layer of tropical mountain rainforest for three years. The results were as follow: At fine, cloudlet and cloud weather in rainy season,the mean value of CO 2 content varied in a range of 349 to 350ml/m\+3 at 2.8m above the canopy, 346 to 348ml/m\+3 at 0.8m above the canopy, 345 to 349ml/m\+3 at 16m inner the forest and 352 to 357ml/m\+3 at 5m above ground in the per...