Abstract: An eddy covariance observation system was established for providing continuous measurements on CO₂ fluxes in an alpine meadow ecological system at the upper reach of the Shule River Basin from 2009 to 2011. Obvious seasonal and inter-annual variations of CO₂ flux were observed. The months, June, July and August, were the strongest absorption period for CO₂ while April, May and October were the strongest release period for CO₂. The net exchange of CO₂ in the three years was 134.5, 151.3 and 194.4 g CO₂/m², respectively, and the mean value was 160.0 g CO₂/m². This indicates that the alpine meadow system played an important role as a carbon sink. During the growing season, the correlations between CO₂ net exchange and the temperature, precipitation, relative humidity, and surface long wave radiation were all negative. When the temperature was higher than 7℃, the CO₂ net exchange increased as temperature increased. In the dormant season, the correlations between CO₂ net exchange and the temperature, precipitation, relative humidity, and surface long wave radiation were all positive. When the surface reflectivity was about 0.2, the trend of the CO₂ net exchange increased fast. When the surface reflectivity was more than 0.3, the CO₂ net exchange reached a maximum and then remained stable.