The content of total polyphenols and flavonoids in eight varieties of potatoes grown in Ningxia was analyzed, and the type and content of phenolic acids in potatoes were determined by high performance liquid chromatography (HPLC). The scavenging capacity of 8 varieties of potatoes against superoxide anions, hydroxyl groups, DPPH, ABTS and ferric iron reduction capacity of FRAP were compared by in vitro antioxidant evaluation model. The results were shown as follows. The highest polyphenol content in Heimeiren was 400.38 mg/100 g, and the lowest in Xiabodi was 233.93 mg/100 g. The highest content of flavonoids was 107.39 mg/100 g in Fiverite, and the lowest in Zhuangshu 3 was 33.17 mg/100 g. Chlorogenic acid was the main kind of phenolic acids in all varieties of potatoes, and Heimeiren had the highest account (91.46%). It was found that chlorogenic acid content was significantly positively correlated with phenolic acids and flavonoids content (P<0.01). The correlation between phenolic acids content and ABTS scavenging ability was the highest, and flavonoid content was significantly negatively correlated with hydroxyl radical scavenging ability (P<0.01). The content of chlorogenic acid had the greatest correlation with ABTS scavenging ability.