Pseudocydonia sinensis Schneid. (Chinese quince) fruits are an excellent source of bioactive compounds. The objective of this study was to evaluate the antioxidant activity, total polyphenol, flavonoid, and phenolic acid content of dry Pseudocydonia sinensis fruits (peel and pulp) of collection from M.M. Gryshko National Botanical Garden (Kyiv, Ukraine). All tested samples (peel and pulp) exhibited DPPH• radical scavenging activities with values from 9.31 to 10.23 and from 5.39 to 6.85 mg TEAC/g, respectively. Antioxidant activity by molybdenum reducing antioxidant power method ranged from 122.0 to 219.31 (peel) and from 62.19 to 95.44 (pulp) mg TEAC/g of dry matter (DM). The total polyphenol content of peel and pulp ranged from 53.17 to 78.67 and from 32.31 to 47.41 mg GAE/g, respectively. The total flavonoid content from 9.15 to 26.18 (peel) and from 0.55 to 0.87 mg.g-1 (pulp) QE. The phenolic acids content of peel and pulp fruits from 4.40 to 8.39 and from 1.12 to 3.97 mg g-1 QE, respectively. The results showed that peel extracts had the highest content of bioactive compounds compared with pulp extracts. Differences between the genotypes were significant in all observed parameters. The polyphenol content presents high positive correlations between antioxidant activity and phenolic content, flavonoid, and phenolic acid. This species is potential for propagation and practice use in Ukraine.