Abstract: The DPPH radical scavenging capacity, hydroxyl radical scavenging capacity, superoxide anion scavenging capacity and reducing power of the four different extracts from Portulaca oleracea L.grown in saline land were studied.The results showed that the DPPH radical scavenging activity and the hydroxyl radical scavenging capacity of four extracts from P.Oleracea grown in saline land were much higher than the superoxide anion scavenging capacity of those in the different radical systems.It demonstrated that the ethanol extract and water extract had a better antioxidant capacity than those from other two extracts.Moreover, the antioxidant capacity of the ethanol extract and water extract had a dose-effect relationship with the mass concentration.