Representative varieties of six different citrus types including ‘Yuhuan Wendan’ (pomelo), ‘Huyou’ (grapefruit), ‘Lunwan navel orange’ (sweet orange), ‘Daidai’ (bitter orange), ‘Ougan’ (mandarin) and ‘Ponkan’ (tangerine) were selected as materials. The main antioxidant active substances of different citrus varieties were identified and purified. The antioxidant activities of citrus extracts from different varieties were compared. By establishing a step-fraction extraction method and purification system, compositions of flavones, flavanones and polymethoxylated flavonoids were purified simultaneously, and 15 monomers were acquired. The results showed that the chemical antioxidant capacities of different segmented products and purified monomers were quite different. The fraction products dominated by flavonoids and flavanones had strong antioxidant capacities, while the fraction products dominated by polymethoxylated flavonoids had poor antioxidant capacities. The flavonoids from the pomelo variety ‘Yuhuan Wendan’ and purities were vicenin-2 (98.72%), rhoifolin (95.78%) and naringin (99.56%); the flavonoids from the grapefruit variety ‘Huyou’ and purities were narirutin-4\mathrm{\prime }-O-glucoside (98.42%), eriocitrin (98.74%) and neoeriocitrin (99.17%); the flavonoid from the sweet orange variety ‘Lunwan navel orange’ and purity was narirutin (98.12%); the flavonoid from the tangerine variety ‘Ponkan’ and the purity was hesperidin (98.00%); the flavonoids from the mandarin variety ‘Ougan’ and purities were neohesperidin (98.56%), poncirin (98.03%), isosinensetin (98.76%), sinensetin (98.77%), nobiletin (99.15%), tangeretin (99.20%) and 5-demethylnobiletin (97.63%). Among the purified monomers, the antioxidant capacities of neoeriocitrin, eriocitrin, hesperidin and neohesperidin were stronger, and they were poorer for nobiletin and tangeretin.