Abstract:Granier’s sap flow system is a precise, sensitive and continuous thermal-electric measurement based on heat balance principle. However, any problem in the installation, measurement and maintenance could have direct impact on the data accuracy and reliability. Basing on many years’ experiential field work, in this paper, we introduce the principle and composition of the Granier’s sap flow measurement system, and focus on discussing the most common problems encountered in the installation and maintenance, hence to assist other users to apply the Granier’s sap flow system successfully.