In this study, the nutritional value, total polyphenol content, total flavonoid content, and antioxidant activity of freeze-dried Cedrela sinensis tender leaf powder were examined. Among the nutritional values, the crude protein, crude fiber, calcium, and potassium were abundantly present in Cedrela sinensis. The Cedrela sinensis powder was extracted with two solvents, 70% ethanol and distilled water (D.W.), to evaluate its functional properties. Total polyphenol and flavonoid contents were measured in the two different extracts, and the extracts were screened for their potential antioxidant activities using tests such as DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), and ABTS radical scavenging assay. Although both extracts exhibited good antioxidant activities against trolox, the ethanolic extract exhibited higher antioxidant activities than the D.W. extract. These results indicated that the Cedrela sinensis powder is a high-valued food ingredient and the extraction with 70% ethanol will be useful as a nutritional source with natural antioxidant activities.