Abstract: In this paper, the heat-pulse technique was applied to study the stem and root sap flow of peach. At the same time, an automatic weather station was used to monitor meteorological parameters. The day-to-day variation of stem and root sap flow, the variation of stem and root sap flow at different depths below the cambium and the variant characteristics of stem sap flow of peach tree under different water status were investigated. The results show that, the day-to-day variant trend of sap flow in the stem is similar to that in the root, the stem and root sap flow rates at different depths below the cambium are various. As well as there are some fluctuations of stem-sap flow under water stress, and the sap flow model developed can forecast the peach transpiration well.