Abstract: 【Objective】 To reveal whether there is a time-scale difference in the influence of soil factors on sap flow of Tamarix chinensis Lour in the hope more accurately analyzing the change law of tamarisk sap flow under different time scales. 【Methods】 The PS-TDP8 tree sap flow monitoring system and 5TM soil temperature and humidity sensor were used to simultaneously observe the tamarisk sap flow rate and soil factors (soil water content SWC and soil temperature Ts) in the southeast of the Kumtag Desert for 5 months. 【Results】 On the monthly scale, Ts_20cm, the main factor that influences the change of liquid flow rate, which could explain 91.7% of the change in flow rate alone. On the daily scale, the entered soil factors were Ts_20cm,Ts_200cm, SWC_50cm, SWC_150cm, SWC_20cm, Ts_20cm, which could explain 72.1% of the change in liquid flow rate, and all the five factors could explain 82.9% of the change in sap flow rate. The soil temperature in the 20cm layer had the greatest influence on the tamarisk sap flow rate on the daily scale. On the hour scale, Ts_20cm had the greatest impact on liquid flow. Ts_20cm could explain 37.6% of the change in liquid flow rate, and six factors together could explain 55.9% of the change in liquid flow rate. 【Conclusion】 Numerous parameters are needed to calculate hourly tamarisk sap flow rate through soil factor simulation, and predicting the monthly sap flow rate requires the fewest parameters and has the greatest reliability. This can better explain the changes in the tamarisk sap flow rate with more accurate prediction.