In this study， the composition of the carotenoids produced by two haloarchaeal strains was identified by ultraviolet/ visible spectroscopy （UV-vis）， thin layer chromatography （TLC） and high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS）. The antioxidant activities of the purified main carotenoid components were then studied. The major carotenoids of Hrr. lipolyticum included bacterioruberin （BR） （84.91%）， monoanhydrobacterioruberin （MABR） （7.87%） and bisanhydrobacterioruberin （BABR） （4.03%）， while those of Srr. litoreum included BR （94.86%） and MABR （1.17%）. The major carotenoid constituents （BR， MABR and BABR） were isolated and purified by column chromatography on silica gel. They all possessed dose-dependent scavenging activities against DPPH and hydroxyl radicals， which were significantly higher than those of β-carotene. It suggested that the C50 carotenoids from halophilic archaea possessed high antioxidant activities. This study provided basis for the exploitation and application of natural carotenoid resources.