This dataset contains the eddy covariance instrument observation data from August 12, 2013 to December 31, 2013 at Dashalong Station on the Heihe Hydrological and Meteorological Observation Network. The station is located in Qilian County, Qinghai Province, with a swamp meadow as the underlying surface. The latitude and longitude of the observation point are 98.9406E, 38.8399N, and the altitude is 3739 meters. The height of the eddy covariance instrument is 4.5 meters, the sampling frequency is 10 Hz, the ultrasonic direction is due north, and the distance between the ultrasonic wind speed temperature instrument and the CO2/H2O analyzer is 15 cm. The original observation data of the eddy covariance instrument is 10 Hz, and the published data is 30 minutes of data processed using Edire software. The main processing steps include outlier removal, delay time correction, coordinate rotation (secondary coordinate rotation), frequency response correction, ultrasonic virtual temperature correction, and density (WPL) correction. Simultaneously evaluate the quality of each flux value, mainly by testing the atmospheric stationarity (Δ st) and turbulence similarity characteristics (ITC). The 30 minute flux values output by Edire software were also screened: (1) data with instrument errors were excluded; (2) Exclude data from 1 hour before and after precipitation; (3) Exclude data with a missing rate greater than 3% every 30 minutes from the original 10Hz data; (4) Exclude observation data of weak turbulence at night (u * less than 0.1m/s). The average period of observation data is 30 minutes, with 48 data points per day. Missing data is marked as -6999. Suspicious data caused by instrument drift and other reasons are marked in red font. The observed data released includes: date/time Date/Time, wind direction Wdir (°), horizontal wind speed Wnd (m/s), lateral wind speed standard deviation Std-Uy (m/s), ultrasonic virtual temperature Tv (℃), water vapor density H2O (g/m3), carbon dioxide concentration CO2 (mg/m3), friction velocity Ustar (m/s), stability Z/L (dimensionless), sensible heat flux Hs (W/m2), latent heat flux LE (W/m2), carbon dioxide flux Fc (mg/(m2s)), mass identification QA-Hs for sensible heat flux, mass identification QA_LE for latent heat flux, and mass identification QA-Fc for carbon dioxide flux. The quality identification of sensible heat, latent heat, and carbon dioxide flux is divided into three levels (quality identification 0: (Δ st<30, ITC<30); 1: （Δst <100, ITC<100）; The rest are 2). The meaning of data time, such as 0:30 representing the average of 0:00-0:30; The data is stored in *. xls format. Please refer to Liu et al. (2018) for hydrological and meteorological network or station information, and Liu et al. (2011) for observation data processing.