This study was designed to evaluate the chemical composition and antioxidant activity of the essential oils of Peucedanum longifolium and P. palimbioides. According to the GC-MS analysis, 35 compounds were accounted for 96.98% of the total oil of P. longifolia. Major components of the oil were 8-cedren-13-ol (33.74%), myristicin (8.03%), germacrene-D (7.73%) and Delta-3-carene (6.38%). In the case of P. palimbioides, 26 compounds were identified comprising the 98.96% of the total oil. The major compounds were described as a pinene (35.45%), (E)-9-octadecenoic acid (23.57%) and beta-pinene (20.19%). In general, P. palimbioides oil exhibited stronger than that of P. longifolia in all test systems. Especially in beta-carotene/linoleic acid system, P. palimbioides showed strong activity against linoleic acid oxidation at 2.0 mg/mL concentration (90.58% +/- 1.56). This value is too close to the synthetic antioxidants BHT and BHA at the same concentration (95.86% +/- 0.23 and 93.05% +/- 1.04, respectively). This plant also exhibited excellent chelating effect (90.39% +/- 0.28) which is obviously greater than that of P. longifolium at 2.0 mg/mL concentration (24.12% +/- 2.50). Chelating effect of the control agent EDTA was measured as 98.78% +/- 0.78 (2.0 mg/mL).