Abstract: Biological characters of Sterculia nobilis Smith were briefly introduced as a native woody plant with edible seeds in South China.Nutritional compositions of the seeds from Guangxi were measured.The antioxidant activities were determined by evaluating reducing power,metal chelating capacity,1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, hydroxyl radical-scavenging activity,and superoxide anion-scavenging activity of polyphenols extraction from the seeds.The results showed that S.nobilis Smith seeds were nutritious,contained eighteen amino acids and abundant polyphenols.The content of starch was 60.42 g/100 g FW, protein was 20.32 g/100 g FW, fat was 2.18 g/100 g FW, amino acids were 2.36 g/100 g FW, Fe was 136.86 mg/100 g FW, vitamin C was 7225 μg/100 g FW, and total phenols were 401.84 μg/mL gallic acid.Polyphenols extraction of S.nobilis Smith seeds expressed rather strong reducing power,metal chelating capacity,DPPH radical-scavenging activity,hydroxyl radical-scavenging activity and superoxide anion-scavenging activity.In the content range of 0-50 μg/mL gallic acid,S.nobilis Smith seeds expressed nearly the same antioxidant activity to that of ascorbic acid and EDTA.Thus,S.nobilis is a potential functional food resource plant due to its comprehensive nutrition and high antioxidant activities.