Abstract:Evapotranspiration from the 3 plant community-types was measured by the method of soil column at Inner Mongolia Grassland Ecosystem Research Station of the Chinese Academy of Sciences. The 3 community-types were typical steppe communities on the zonal habitat dominated by Leymus chinensis or Stipa grandis, the Artemisia intramongolica community on the sand lands, and the Agrostis alba meadow community on the river floodland. The results were as follows: 1. The transpiration from the meadow community was the highest (9.2 mm · d-1), being the 2--3 times of the other two communities; while the evaporation from the meadow was the lowest evaporation (0.4mm·d-1),being only 1/4 of that from sandylands or 1/8 of that from steppe. 2 A compartive measurement of the evapotraspiration from the two typical steppe communities dominated by L. chinensis and S. grandis showed that the evapotranspiration from L. chinensis community(4.4—5.0mm· d-1) was higher than that from S. grandis community (3.5—3.8mm· d-1).Ratio of transpiration to evaporation (T/E)was also much higher in L. chinensis community (=2) than in S. grandis community (= 1 ). 3. The seasonal chenge of evapotranspiration from L. chinensis community was in accordance with the change of air temperature; but showed a big flactuation due to change of rainfalls. The water budget of the community was aproximately balance.