Objective To study the nutritional components and in vitro antioxidant activities in different parts of Eucommia ulmoides.Methods The content of protein, fat, ash, vitamin C, polysaccharides, flavonoids, and chlorogenic acid in different parts of E. ulmoides is determined according to the methods specified in national standards. The antioxidant activities of different parts of E. ulmoides are evaluated based on the ABTS⁺ free radical scavenging ability, DPPH free radical scavenging ability, and total reducing power.Results There are statistical differences in the content of essential nutrients among different parts of E. ulmoides (P<0.05). The ash content and fat content are the highest in the leaves, reaching 13.65 and 6.19 g/100 g, respectively. The protein content and Vc content are the highest in male flowers, reaching 20.8 and 13.9 g/100 g, respectively. The total flavonoids, chlorogenic acid, and polysaccharides are the highest in the leaves, reaching 2.45, 1.61, and 1.27 g/100 g, respectively. The results of in vitro antioxidant activity assay show that male flowers have the highest total reducing power, with the IC₅₀ of 10.2 μg/mL. The leaves have the highest ABTS⁺ free radical scavenging ability and DPPH free radical scavenging ability, with IC₅₀ being 11.19 and 11.40 μg/mL, respectively. The comprehensive evaluation results of membership function method show that the antioxidant effect of the leaves is the best, and that of the cortex is the weakest.Conclusion The nutritional value and antioxidant properties of E. ulmoides vary among cortex, leaves, and male flowers. E. ulmoides leaves with both edible and medicinal properties demonstrate certain nutritional value in the development and utilization of food raw materials in the future.