The quantitative modeling of root water exaction is difficult in research on soilroot hydraulic dynamics. Present models were constructed under certain ideal conditions and based on poor understandings of the mechanisms of root water exaction and thus their applications were rather limited. The minimum energy model was presented based on the physical concept that plant would consume minimum energy for root water exaction in order to survive. But it is not clear if this theory could truly reflect root water exaction. In this research,a soil column experiment was conducted to validate the model. Results indicate that the model had a higher modeling precision under normal water condition, while the modeling precision decreased under drought condition. The reason may be related with the biological mechanism inside plant themselves.