Species S. brachyodon and S. officinalis are object of scientific research by modern medicine and are highly appreciated by tradional medicine. While in past they were appreciated because of its aroma and quality of their essential oil, today they are studied for their content of flavonoids and phenolic acids which are very potent antioxidants. In this study the amount of flavonoids was determined by spectrophotometric method according to Christ and Müller, as well as phenolic acids by procedure in European Pharmacopoeia. The study also included DPPH assay. The result of DPPH test were expressed as miligrams of equivalent of gallic acid per gram of plant material. For statistical analysis of data Student t-test was used. The highest amount of flavonoids, in species S. brachyodon, was determined in sample of leaves from 2016, while the lowest amount was determined in sample of flowers from year 2015. In species S. officinalis the highest quantity of flavonoids was determined in sample of leaves collected in Pharmaceutical Botanical Garden „Fran Kušan“, while the lowest quantity was determined in sample of leaves - Naturavita. The highest amount of phenolic acids, in species S. brachyodon, was determined in sample of leaves from 2016, while the lowest amount was determined in sample of stalks from 2015. In species S. officinalis the highest content of phenolic acids was determined in samples of leaves collected in Pharmaceutical Botanical Garden „Fran Kušan“, while the lowest content of phenolic acids was determined in sample of leaves - Biokovo. The highest antioxidative effect of ethanolic extracts, in species S. brachyodon, was determined in sample of leaves from 2015, while the lowest effect was determined in samples of stalks and flowers from 2015. In species S. officinalis the highest antioxidative effect of ethanolic extracts was determined in sample of leaves - Suban, while the lowest effect was determined in sample of leaves - Biokovo. In species S. brachyodon, the highest antioxidative effect of acetonic extracts was determined in samples of leaves from 2016, while the lowest effect was determined in sample of stalks from 2015. Among acetonic extracts of species S. officinalis the highest antioxidative effect was determined in sample of leaves - Suban, while the lowest effect was determined in sample of leaves - Biokovo.