Abstract: Eddy covariance technique was adopted in measuring the evapotranspiration (ET) from a typical marsh in Sanjiang Plain in the growth season (May to September) of 2006. After analyzing the seasonal variation of the ET, the daily ET from the marsh was estimated by using PenmanMonteith (PM) and Priestley-Taylor (PT) models, and the estimated values were tested by the measured values. The results showed that the ET from the marsh had an obvious seasonal variation, with the lowest month-average daily ET in May and the highest one in July. The average daily ET in growth season was 194 mm·d^-1, and the total ET was 293 mm. The daily ET estimated by PM model was significantly lower than the measured one during the early and late growth seasons. A good match was observed between PT-estimated values and measured values throughout the growth season. Considering its accuracy and simplicity, PT model was more suitable for the simulation of marsh ET.

Key words: intercropping, oriental melon, yield, growth and development, quality, mineral element