This study is outlined to define the chemical composition, total phenols, flavonoids, flavonols, Reducing power and in vitro antioxidant activity of the extracts of Froriepia subpinnata and Er-yngium campestre from Iran. The chemical compositions of F. subpinnata and E. campestre were analysed by GC–MS. Sixteen and ten compounds were detected in the leaves essential oils of F. subpinnata and E. campestre at the first vegetative phase. The major compound of the essential oils of F.subpinnata and E. campestre were terpinolene(34%) and limonene(62.73%), respectively. Total flavonoid and flavonol contents were calculated as quercetin equivalents from a calibration curve. The highest total phenolic and flavonoid contents were observed in F. subpinnata in the second vegetative phase. An¬tioxidant activity was determined by DPPH assay. The highest radical scavenging activity was observed in F.subpinnata -2(86.1±0.89% inhibition), followed by E. campestre-2(83.61±0.73%), F. subpinnata-1(77.41±0.85%) and E. campestre-1(76.72±0.93%).