The application of silicon increased the amount of soil water maize roots absorbed.The amount of xylem sap increased by 3.6% to 9.4% compared with the control.The transpiration rate of maize decreased by 26.0% to 39.7% and water use efficient were improved by the application of silicon.The morphology and structure of cells in maize leaves was changed and osmosis of water in plant tissues inhibited.So the application of silicon significantly improved water conditions in maize plants and created a better basis for the increase of maize crop yield.