Abstract:Antioxidant activity ofextracts from different parts of Amaranthus tricolor L.was studied.Using 75% ethanolsolution，roots，stems and leaves of Amaranthus tricolor L.were conducted to ultrasonic extraction，respectively.Further more，the effects of Amaranthus tricolor L.extracts on scavenging superoxide free radical，DPPH radical and hydroxyl radical，total antioxidant capacity and reducing power were evaluated.The results found thatleaf extracts from Amaranthus tricolor L.showed the strongesteffects on scavenging superoxide radical and DPPH free radical，and had the biggest total antioxidant capacity，while the stem extract had the strongest effects on scavenging hydroxyl free radical.Different parts of Amaranthus tricolor L.especially leaves have a good antioxidant activity.