The results of the evaluation of promising 24 cultivars and 6 forms of garden strawberries by their chemical composition (contents of ascorbic acid, titrated acid, sugars, dry substances, monosaccharides, the level of the sugar-acid coefficient) and the taste qualities of the fruits are presented to identify sources of high taste qualities and high content of biologically active substances. Seven cultivars and forms (Aidarina, Assol, Zarina, Efsane 3-15 Atlantida × Uniol, 12-15 Sunrise × Hercules, 25-15 Jantarnaja × Zenga Zengana) with a high fruit flavor (4.8-5.0 points); six cultivars (Aidarina, Assol, Atlantida, Bagryana, Zarina, Present) with an increased content of ascorbic acid (76.1-85.4 mg/100 g); eight cultivars and forms (Bagryana, Hercules, Krymskaya Remontantnaya, Luiza, Sanika, Honey, 3-15 Atlantida × Uniol, 14-15 Sunrise × Clery) with high titratable acidity (1.1-1.2%); five cultivars (Aidarina, Albion, Bagryana, Zarina, Rusanovka) with optimal total sugar content (7.5-9.8%); four cultivars (Albion, Bagryana, Krymskaya Remontantnaya, Uniol) with a high amount of dry matter (10.6-17.3 %); seven cultivars and forms (Assol, Albion, Zarina, Krymskaya Rannaya, Rusanovka, 13-15 Sunrise × Zenga Zengana, 14-15 Sunrise × Clery, 25-15 Jantarnaja × Zenga Zengana) with a high sugar-acid index (8.0-11.9). The lowest variability (8.2-16.7%) was characterized by such signs as the taste of fruits and the content of total sugar, titrated acidity, and the highest (18.3-25.0%) - the content of ascorbic acid, solids, and the sugar-acid index. The most significant correlation between the sugar-acid coefficient and the biochemical parameters of strawberry fruits was revealed.