Abstract: In order to estimate the transpiration（T_r） and soil evaporation（E_g） of cucumber plants in greenhouse conditions, based on the micro-meteorological data（measured in a greenhouse in spring-summer and autumn-winter planting seasons in 2018）, cucumber crop leaf area index（LAI） and root soil moisture data in the area, the parameters in the dual crop coefficient model（Dual-K_c） and Priestley-Taylor（P-T） model recommended by FAO-56 were corrected, and the revised Dual-K_c and P-T models were applied（M-PT） to estimate greenhouse cucumber evapotranspiration（ET_c）. The measured data of spring-summer and autumn-winter crops in 2019 were used to verify the accuracy of the model. The results show that the ET_c and T_r calculated by the improved Dual-K_c and M-PT models have a good agreement with the measured values, and the performance of the Dual-K_c model is better than that of the M-PT model. The root mean square error（RMSE）, mean absolute error（MAE）, deviation rate（Bias） and correlation coefficient（R~2） of the Dual-K_c model in predicting cucumber ET_c are 0.36 mm/d, 0.28 mm/d,-0.10 and 0.98 for spring-summer planting season, and 0.28 mm/d, 0.22 mm/d,-0.11 and 0.97 for autumn-winter planting season, respectively. The RMSE, MAE, Bias and R~2of M-PT model are 0.48 mm/d, 0.42 mm/d,-0.17 and 0.97 for spring-summer planting season and 0.41 mm/d, 0.31 mm/d,-0.24 and 0.95 for autumn-winter planting season, respectively. Although M-PT model has a slightly higher estimation error than Dual-K_c model, its simple structure and fewer parameter requirements make it more worthy of application in the estimation of greenhouse crop evapotranspiration（ET_c）.