Field observations for two consecutive years were carried out on the actual evapotranspiration, water vapor flux and latent heat flux(LE)for two consecutive years in the vegetable land in the suburb of Yueyang City, Hunan Province by using eddy covariance technique based on closed-path QCLAS-EC Analyzer. The original observation data were processed and the evapotranspiration was calculated so as to analyze the annual periodic change trend and seasonal variation law of the regional evapotranspiration. The results show that annual evapotranspiration in the study area were between 730 and 803 mm; the seasonal variation was substantial, reaching the highest level in August, 3. 5 mm/d and in January, only 0. 4mm/d. The actual evapotranspiration in the whole study area can be summarized as follows: higher in spring and summer, lower in autumn and winter; higher in planting season, lower in non-planting season; higher at midday and afternoon, lower at night. In addition, the effects of different agricultural activities on the actual evapotranspiration were observed by using high-resolution measured data. The findings are that the evapotranspiration was increased by planting and was decreased by harvesting, and the reduction of evapotranspiration by harvesting was significantly higher than that by planting. While irrigation also contributed to the promotion of evapotranspiration but was less pronounced, the effect of final fertilization on evapotranspiration was not yet clear.