This study was conducted to investigate the antioxidant activity and physiological properties of Moringa (Moringa oleifera Lam.) leaves extracted with three different solvents (water, ethanol, and methanol). The extraction yield from water, methanol, and ethanol were 13.17, 9.54, and 7.48%, respectively. The highest total polyphenol content (58.04 mg/100 g) and total flavonoid contents (12.36 mg/100 g) were observed in water extract. The DPPH radical scavenging activity was the highest in the water extract (79.18%) at the 500 mg% level, similar to BHT (77.18%). Additionally the same tendency was observed with DPPH, ABTS radical scavenging ability, and ferreous ion chelating ability. The water extract showed relatively high antioxidant activities. The angiotensin I-converting enzyme (ACE) and the HMG-CoA reductase inhibitory activity of water extract at a concentration of 500 mg% were somewhat higher than those of the other extracts. Additionally, the HMG-CoA reductase inhibitory activity of the water extract was significantly slightly lower than that of the positive control (cholorogenic acid). These results suggest that Moringa leaves extracted with water will be useful as antioxidant-rich and functional natural foods.