Background & Aim:Extracts of Roselle calyx, possess compounds which could be considered as a great source of natural antioxidants. In this project, antioxidant activities, phenolic compounds content and their correlation analysis on calices of Roselle (Hibiscus sabdariffa) was investigated. Experimental: Total polyphenolic compound, flavonoids and anthocyanins were determined spectrophotometrically. Catalase and peroxidase activity was estimated based on unit per milligram protein. Total antioxidant capacities of the extract were studied using phosphomolybdate assay, DPPH assay and FRAP method. Results: The hibiscus calices were rich in phenolic compounds, flavonoids and anthocyanins. Peroxidase and catalase activity was estimated as 3.13 and 0.05 unit mg-1 protein, respectively. Calyx extract showed high antioxidant activities specially based on DPPH assay. Correlation analysis was also performed between parameters. There was a positive significant correlation between the levels of polyphenolics and flavonoids, anthocyanins and antioxidant capacity of calices at PRecommended applications/industries: Extracts of H. sabdariffa L. (sabdariffa) calices are rich in antioxidant compounds including total phenolic compounds, flavonoids content, and anthocyanins. Based on all the method of measuring antioxidant capacities in this project, the calices showed an acceptable antioxidant activity. Thus, H. sabdariffa L. (sabdariffa) may be suggested as a potential source of natural antioxidants in food and pharmaceutical industry. پرونده مقاله