The ascent of sap in plants has been explained with the theory of root pressure(+) and cohesion-tension(-). Hypothesis of Embolism and repair mechanism could not be accepted untill novel refilling introduced to secrete sugar into xylem by xylem parenchyma cell, becauce it had been regarded as the simple physical phenomena able to recover by meniscus of water, surface tension and transpiration. Now xylem is not the dead tissue no more, but active with the aid of axial xylem parenchyma tissue to endure the environmental water stress by the interaction of phloem. Stomatal closure and embolsm are the resistant defence devices and embolism to avoid the water loss as safty-fuse in electric current wires, could be restored with sugar excretion and aquaporin biosynthesis by both physiological control and genomic regulation. Hence, Root pressure and embolism repair could be understood by the same principle that the power of osmotic differ be the driven-force of water flow. Analogy for the embolism is blood blocking of human circulation. because capitation is likely to blood atheroma. Reaching to death will be the same in plant and human when blocking of tube can not be removed.