Abstract: Purpose: Cadmium (Cd) is toxic to rice seedlings. Studies showed that selenium (Se) could alleviate Cd toxicity in rice seedlings. However, the effect of Se on the accumulation of Cd in mature rice plants and Se accumulation in grain and the quality and dietary intake risk of brown rice are rarely investigated.Methods: A rice pot experiment was performed with Se-treated Cd-contaminated paddy soil to explore the effect of Se on Cd accumulation of mature rice plants and the yield and quality of the rice grain, as well as the health risks of consuming rice grains.Results: Adding Se significantly increased the rice grain yield, decreased Cd concentrations in the tissues of rice plants, and significantly decreased protein and amylose concentrations in brown rice, which helped improve the taste and quality of the cooked rice. Adding Se decreased the health risk index of Cd and increased the daily intake of Se for humans by consuming rice; however, excessive Se addition resulted in Se in rice grain exceeding the Tolerable Upper Intake Level.Conclusion: An appropriate dosage of Se can decrease Cd accumulation in rice, increase yield and Se accumulation, and ensure its edible safety.