The objective of this study was to investigate the effect of different ethanol ratios in extraction solvent as well as the antioxidant properties of five plants. Thyme, mint, uckun, grape seeds and green tea waste fiber was analyzed to determine total phenolic content (TPC) and antioxidant activity by ABTS and DPPH radical scavenging activity assays. Individual phenolic components were analyzed with reverse phase high performance liquid chromatography (HPLC). TPC varied significantly from 2.00±0.27 to 172.68±0.19 mg GAE g-1 dw depending on the plant type and ethanol ratio of the solvent. The effect of ethanol ratio also varied among different plants. HPLC analysis was performed for the extracts showing highest antioxidant activity, and green tea waste fiber (699.89 mg 100 g-1 dw) had the highest concentration of phenolic compounds overall, while mint (173.67 mg 100 g-1 dw) had the lowest amount. Correlations between TPC and antioxidant activity was significant which is comparable to the previous report.