Panax notoginseng and Carthamus tinctorius are known as traditional medicinal plants, and they also have edible values. To better understand their pharmacological mechanism, the present study assessed the in vitro antioxidant activities of extracts of P. notoginseng (EPN) and C. tinctorius (ECT). In addition, the main components of EPN and ECT were determined by HPLC. The results show that EPN mainly contained saponins, which were effective in scavenging (.)OH and O(.)(2-), while showing a low activity in the DPPH(.) assay. Flavonoids were the main components of ECT and were active in scavenging all three radicals in a dose-dependent manner. In brief, the antioxidant properties of EPN and ECT are distinct and might be complementary, their combined use tending to be more effective in scavenging (.)OH (P<0.05 vs. EPN or ECT).