Physiochemical characteristics of Luffa cylindrica (L.) Roem and antioxidant activities of its four extracts were analyzed. The chemical composition of L. Roem contained 93.69% moisture, 1.64% crude fiber, 0.52% crude protein, 0.27% crude fat, and 0.06% crude ash. The major minerals were potassium, phosphrous, and calcium. We also analyzed the major organic acids, acetic acid and succinic acid. In free amino acids, ${eta}$-aminoisobutyric acid showed the highest concentration (100.74 mg/100 g), followed by phosphoethanolamine, urea, asparagine, and valine. Glutamic acid was the highest hydrolyzed amino acid with 1,039.99 mg/100 g followed by aspartic acid, lysine, and arginine. Four extracts from L. Roam, hot-water (LCH), cold-water (LCC), 80% ethanol (LCE), and methanol (LCM), were prepared. Total phenolic and flavonoid levels of LCE exhibited higher than three extracts. The antioxidant potential of extracts from L. Roem were investigated using DPPH, ABTS, and NBT assays. Of the four extracts, LCE had relatively high antioxidant capability on DPPH and superoxide anion radical scavenging activities (12.13%, 16.88%, and 26.61%). Based on the above results, it is suggested that an 80% ethanolic extract from L. Roem was a natural antioxidant material for health food and should be a good ingredient for functional food.