In this study, lysimeters were used to measure evapotranspiration (ET) of Alfalfa, Caragana, and Artemisia capillaries in water-wind erosion crisscross regions in the Loess Plateau. The measured ET and Penman-Monteith equation were used to determine crop coefficient (KC), and the effects of vegetation height and coverage and precipitation on the ET were analyzed. The results show that the Logistic model can be used accurately to simulate the changes of the height and coverage of the three types of vegetation. The daily ET variations of these three types of vegetation were significantly affected by precipitation, indicating that evapotranspiration processes were controlled by the soil water content in the arid region. There was no meaningful difference in the monthly ET among the three types of vegetations. The total ET of Alfalfa, Caragana and Artemisia capillaries were 316.8mm, 317.7mm and 361.9mm, respectively. The crop coefficients of Alfalfa in initial, middle and end growing periods were 0.48, 0.54, and 0.42 respectively. The crop coefficients of Artemisia capillaries in initial, middle and end growing periods were 0.58, 0.67 and 0.62 respectively. Crop coefficients of Caragana in initial and middle growing periods were 0.45 and 0.57 respectively and those values are higher than that of local typical food crop.