Medicnal and aromatic plants are used in different fields depending on the amount of antioxidant and phenolic substances they have. This study was conducted to determine the antioxidant enzyme activity and phenolic contents of some species of the Asteraceae family (Achillea biebersteinii Afan., Achillea millefolium L., Achillea nobilis L., Artemisia absinthium L., Artemisia alba Turra., Artemisia dracunculus L., Artemisia santanicum L., Artemisia vulgaris L., Carthamus tinctorius L., Centaurea cyanus L., Echinacea pallida Nutt., Echinacea purpurea L. Moench., Grindelia robusta Nutt., Helianthus annuus L., Helichrysum plicatum L., İnula helenium L. and Santolina chamaecyparissus L.) for medicines, additive food supplement and cosmetic sector. In, this study, the antioxidant amount of some medicinal and aromatic plants with different properties belonging to Asteraceae family and hormones, phenolic substance and vitamin C and vitamin E were determined. E. purpurea, A. nobilis, G. robusta and S. chamaecyparissus species have more antioxidant, enzymes, hormones and some phenolic substances such as vitamin C and vitamin E, than other species in Asteracae. According to study result, highest amount of gibberellic acid, salicylic acid, indole acetic acid (IAA), abscisic acid (ABA), catalase (CAT) enzyme activity, peroxidase (POD) enzyme activity, superoksid dismutase (SOD) enzyme activity, ascorbate peroxidase (AxPOD) enzyme activity, malondialdehyte (MDA), hydrogen peroxide, total antioxidant, total phenolic, total carotenoid amount, vitamin E contents, vitamin C contents, chlorogenic acid contents, caffeic acids, chloric acid and proantocyanidin were determined in the A. millefolium (819.46 ng μl ⁻¹ ), A. dracunculus (91.29 ng μl ⁻¹ ), S. cyparissus L. (1985.08 enzyme unit (EU) g leaf ⁻¹ ), S. chamaecyparissus (415.22 EU g leaf ⁻¹ ) E. purpurea (83.78 EU g leaf ⁻¹ ), A. nobilis (41.91 EU g leaf ⁻¹ ), S. chamaecyparissus (140.85 nmol g ⁻¹ ), E. purpurea (10.49 μmol g ⁻¹ ) A. nobilis (1464 μmol Trolox Equivalents (TE) per g ⁻¹ ), E. purpurea (13.34 mg gallic acid (GA) per g ⁻¹ fresh weight (FW)), E. purpurea (29.41 g vitamine A 100 ⁻¹ ), G. robusta (33.63 g-Alfa tocopherol eg 100 g ⁻¹ ), A. nobilis (20.70 g 100g ⁻¹ ), E. purpurea (13.51 mg g ⁻¹ fw), A. nobilis and S. chamaecyparissus (1.83 mg g ⁻¹ fw), S. chamaecyparissus (143.84 mg g ⁻¹ fw) and A. nobilis (83.63%) species, respectively. According to the results obtained, it is determined that there are significant changes in the contents of the medicinal and aromatic plants depending on the region and climatic conditions.