Silicon was a beneficial element to many higher plants. Silicon can benefit a crop by promoting its growth and development, increasing its production, and improving its resistance to abiotic and biotic stresses. However, the detailed and comprehensive studies on how silicon applications could enhance the resistance of maize to drought stress are still lacking. Therefore, we conducted a pot experiment to investigate effects of silicon application on water metabolism in maize plants under drought stress. The results showed that silicon application decreased transpiration rate of maize plants from the early to middle stages of drought stress, but helped in maintaining a relatively higher transpiration rate at a later stage. Silicon application reduced stomatal conductance under drought stress. Therefore, leaf water content and water potential in silicon-supplied maize plants were higher than those in silicon-deficient maize plants. As a result, biomass of silicon-supplied plants was higher than that of silicon-deficient plants under drought stress. These results suggest that silicon can significantly reduce stomatal conductance and thereby decrease the transpiration rate in maize plants. Thus, silicon application enhanced drought resistance in maize plants by increasing of the water-holding capacity and improving water relations