Abstract: In order to be master of the rule of water transpiration of gingkgo(G. biloba), and open out the mechanism of physiology action, The Thermal Dissipation Probe (TDP) was used in this experiment to monitor the dynamics of gingkgo (G. biloba) trunk sap flow in different growing periods, and an Automatic Weather Station was synchronously applied to measure the environmental parameters. The results indicated that change of sap flow was shown significantly different in fine day, cloudy day and in rainy day, daily cumulative flux of fine day>cloudy day’s>rainy day’s; The seasonal change trend of sap flow revealed that transpiration flux was the most in Jul., daily sap flow flux could reach around 23L.Daily sap flow flux fluctuating was relatively distinct in May, July and Sep., most distinct in Jul, discrepancy could reach 20L.According to average daily sap flow flux of different growth phases, transpiration flux of gingkgo of 12a was 2580L during 2006-growth season; Changes of sap flow flux in a growing season accorded with seasonal changes of temperature, soil relative humidity, soil temperature, relative humidity, PAR and rainfall. Stepwise regression analyses revealed that temperature was the main environmental factor influencing on sap flow, stepwise regression equation shows it reaches significant level.