Abstract: To compare the contents of antioxidant components and antioxidant activities in different purple sweet potato varieties from Fujian province,total phenolic content,flavonoids,anthocyanins and anthocyanidins in 7 kinds of purple potatoes were determined and radical scavenging activities of fresh purple potatoes were investigated. The Funingzi No.3 purple sweet potato had the highest levels of antioxidant components,such as total phenolic content,flavonoids,anthocyanins and anthocyanidins. The main anthocyanidins in purple sweet potatoes were delphinidin,malvidin,peonidin and cyanidin. There were some differences of anthocyanidins kinds and contents in purple potato samples. The results also showed that Funingzi No.3 exhibited much higher radical scavenging activity. When the concentration of sample was 0.5 mg·L^-1,scavenging rate of DPPH,OH and ABTS were 88.4%、49.1% and 90.1%,respectively. Relatively,Funingzi No.3 contained richer antioxidant compounds and showed much better antioxidant activities in vitro.