The objectives of this research were to study antioxidant activities from various extracts of five Citrus peels using two methods of antioxidant assays which were DPPH (2.2-diphenyl-1-picrylhydrazyl) and CUPRAC (Cupric ion Reducing Antioxidant Capacity); and correlation of total flavonoid, phenolic, and carotenoid content in various extracts of five Citrus peels with IC50 of DPPH antioxidant activities and EC50 of CUPRAC antioxidant capacities. Extraction was performed by reflux apparatus using different polarity solvents. The extracts were evaporated using rotary evaporator. Antioxidant capacities were tested using DPPH and CUPRAC assays. Determination of total phenolic, and carotenoid content performed by UV-visible and their correlation with IC50 of DPPH antioxidant activities and EC50 of CUPRAC antioxidant capacities were analyzed by Pearson’s method. Ethyl acetate extract of C.sinensis peels (MA2) had the lowest IC50 of DPPH scavenging activity 11.04 μg/ml, while n-hexane extract of C.sinensis peels (MA1) had the lowest EC50 of CUPRAC capacity 22.93 μg/ml. Ethyl acetate extract of C. sinensis (MA2) the highest total phenolic content (431.3 mg GAE/100 g), MA1 had the highest total flavonoid content (2037.1 mg QE/100 g), and the highest total carotenoid content (509.5 mg BE/100 g). There was a negatively high correlation between total phenolic content in C. aurantifolia peel extracts with their IC50 of DPPH scavenging activity and EC50 of CUPRAC assays. The IC50 of DPPH scavenging activities in C. aurantifolia, C. limon, C. maxima, C. sinensis peel extracts gave linear result with EC50 of CUPRAC capacities.