[Objective] To discuss the effects of aluminum stress on the stomata characteristics and photosynthesis of Scutellaria baicalensis Georgi seedlings, so as to provide a theoretical basis for revealing the aluminum toxicity mechanism on plants. [Method] Scutellaria baicalensis Georgi seedlings at 6 true-leaf stages were treated with different concentrations of aluminum at 0.1, 0.5, 2.0 and 5.0 mmol/L. After 30 days, the leaves were harvested for determining stomata characters including area and density, and photosynthesis indexes such as net photosynthetic rate, transpiration rate and stomata conductance. [Results] Aluminum stress could lead to significantly reduce the stomata length, stomata width and stomata area, but stomata density was improved. The net photosynthetic rate, transpiration rate and stomata conductance decreased significantly with the increase in aluminum concentration, but the intercellular CO2 concentration was significantly increased. [Conclusions] It was non-stomata factors that leaded to the restraint of photosynthesis, meanwhile high-concentration aluminum might result in the bad effects on the adaptability of Scutellaria baicalensis Georgi to environment. [Objective] To discuss the effects of aluminum stress on the stomata characteristics and photosynthesis of Scutellaria baicalensis Georgi seedlings, so as to provide a theoretical basis for revealing the aluminum toxicity mechanism on plants. [Method] Scutellaria baicalensis Georgi seedlings at 6 true-leaf stages were treated with different concentrations of aluminum at 0.1, 0.5, 2.0 and 5.0 mmol / L. After 30 days, the leaves were harvested for determining stomata characters including area and density, and photosynthesis indexes such as net photosynthetic rate, transpiration rate and stomata [Results] Aluminum stress could lead to significantly reduce the stomata length, stomata width and stomata area, but stomata density was improved. The net photosynthetic rate, transpiration rate and stomata conductance decreased significantly with the increase in aluminum concentration, but the intercellular CO2 concentration was significantly increased. [Conclusions] It was non-stomata factors that leaded to the restraint of photosynthesis, meanwhile high-concentration aluminum might result in the bad effects on the adaptability of Scutellaria baicalensis Georgi to environment.