Abstract:The content of carbon dioxide ranges from 333ml/m\+3 to 350ml/m\+3 in rainy season appeared in the time range from 8:00 to 18:00 and height range from 16 m to the canopy top in a tropical mountain rain forest. The CO 2 content range in rainy season was 7~22ml/m\+3 less than that in the dry season. At night the maximum content of carbon dioxide was 5m above the forestland and appeared different time in both weathers.Diurnal (8:00 ~18:00) vertical grade (ΔC t/ΔZ) of carbon dioxide above the canopy sh...