Drought stress is one of the major constraints for rice production in the rainfed lowlands in the world. Silicon (Si) has been verified to play an important role in increasing plant resistance to biotic and abiotic stress, although it is not considered an essential element to higher plants. In addition, there were some reports about the beneficial role of Si in alleviating drought stress, yet the mechanism is still poorly understood. Here, two near-isogenic lines of rice (Oryza sativa L.), w-14 (drought susceptible) and w-20 (drought resistant), were chosen to study the effects of exogenous Si application on the growth traits, photosynthetic characteristics and mineral nutrient absorption of rice plant under drought stress. Water was withheld 10 days during heading stage. The results showed that 1.5 mmol/L Si supply had no significant effects on growth and physiological parameters of rice plants under well-watered conditions. Drought stress was found to reduce dry weight, leaf water potential, photosynthetic parameters, basal quantum yield (Fv/F₀) and maximum quantum efficiency of PSⅡ photochemistry (Fv/Fm) in rice plants, while Si application significantly increased dry matter accumulation, water utilization efficiency, water potential, chlorophyll content, Fv/Fm and Fv/F₀, photosynthetic rate (Pr), transpiration rate (Tr) of leaves for both rice lines under drought stress, but stomatal conductance (G_s) and intercellular CO₂ concentration (Ci) were decreased. Silicon content in leaves was significantly increased by Si treatment whether drought stress occurred or not. In addition, Si supply could influence mineral nutrient level of rice leaves. Significant increase in the content of inorganic ions level of leaves were found in the two near-isogenic rice lines under drought stress, but Si treatment significantly reduced these ions, K⁺、Na⁺、Ca²⁺、Mg²⁺、Fe³⁺ content in leaves were reduced by 16.38%, 24.50%, 19.70%, 21.52% and 18.58% for line w-14, 11.64%, 12.11%, 16.06%, 11.11% and 19.15% for line w-20, respectively. These results suggested that silicon application is useful to alleviate drought stress of rice through the enhancement of photochemical efficiency and adjustment of the mineral nutrient absorption in rice plants.