Consumption of Camellia sinensis L (tea), a popular beverage, is very common today. In addition to consuming tea as a beverage, it is suggested that it can also be added to other foods to increase their antioxidant activities. This study aimed to determine the antioxidant capacity, total phenolic, and total flavonoid contents of extracts prepared in different solvents of tea grown in soil treated with boric acid. The area in Rize/Turkey was divided into 4 groups. No application was made to the control group (B0 group). Boric acid prepared in sodium tetraborate buffer was applied to the other three areas as a single dose at concentrations of 100 (group B1), 300 (group B3), and 500 (group B5) mg/m2. The obtained tea leaves were ground and infused in water, 20% ethanol, and 50% ethanol by the classical infusion method. The extracts obtained after infusion were analyzed for total phenolic contents, flavonoid content, and antioxidant capacity. It was determined that 20% and 50% ethanol were a better solvent than water in terms of total phenolic content, flavonoid content, and antioxidant capacity. Although the total phenolic contents of tea leaves grown in soils treated with different doses of boric acid did not change, differences were observed in their flavonoid contents and antioxidant capacities. As a result, we can say that boric acid should be at a certain dose to improve the quality of the tea plant. In addition, different solvents can be used to reveal more of the tea content.