Platycladus orientalis trees in northern China were studied to accurately estimate how much water they use. Different models were used to predict evapotranspiration, with the APM model being the most accurate. The PT and HS models overestimated water use in hot months and underestimated it in cold months. Factors like wind speed, temperature, and precipitation affected the accuracy of the models. The PT model was adjusted to include humidity, and the HS model was modified to improve accuracy.