Rice OXHS4 gene controlling root growth and conferring enhanced drought resistance, and use thereof in genetic improvement of rice drought resistance is provided. OXHS4 gene is cloned using candidate gene screening method. Drought stress experiments at seedling stage and adult plant stage shows that overexpression of OXHS4 gene can improve drought resistance of transgenic rice, while the oxhs4 mutant exhibits sensitivity to drought, showing the function of said gene and the use thereof.