Abstract: In this study, we investigated the changes in bioactive compounds in wild and cultivated Hypericum perforatum during introduction and acclimatization. Physiological and biochemical characteristics, bioactive compound contents, and antioxidant capacity were evaluated for H. perforatum plants at the flowering stage. The net photosynthetic rate, transpiration rate, stomatal conductance, chlorophyll content, and root activity were higher in cultivated plants than in wild plants. The flowering date was 7 days earlier in the cultivated plants than in the wild plants, and the dry weight of aboveground parts was 16.67% higher in cultivated plants than in wild plants. The total flavonoid and hypericin contents in the same organ did not differ significantly between the wild and cultivated plants. The total phenolic contents in flowers were higher in wild plants than in cultivated plants, while the opposite trend was observed for total phenolic contents in the leaves. Both wild and cultivated plants had higher total flavonoid and phenolic contents in the flowers and leaves than in the stem, while the highest hypericin content was in the flowers, followed by leaves, and then stems. The antioxidant capacity of the wild and cultivated plants was highest in the flowers followed by leaves, and then stems. There was no difference in the antioxidant capacity of leaf and stem extracts between wild and cultivated plants, while the antioxidant capacity of flower extracts was significantly stronger in cultivated plants than in wild plants. These results indicate that the cultivated plants not only showed strong acclimatization abilities, but also had bioactive compound contents and an antioxidant capacity similar to those of wild plants.