Basil (Ocimum basilicun L.) belongs to the family Lamiaceae and is an important aromatic and medicinal plant, which it widely cultivated in many countries. This plant is a good source of phenolic com- pounds and natural antioxidants. The main aim of present study was to determine effect of jasmonic acid on total phenolic content and antioxidant activity of ethanolic extract from the aerial parts of the purple and green landraces of basil. The pot experiment was conducted in an experimental field with cold and semiarid climate in southwestern Iran. Treatments comprised control (water), ethanol as solvent, 200 and 400 pLjasmonic acid. The total phenolic content of the extract by Folin-Ciocalteu method and the antioxidant activity using DPPH assay were determined. Results indicated that the different levels of jasmonic acid had significant effects on total phenolics content and antioxidant activity of the extracts. Foliar-applied jasmonic acid in particular 400 μL increased total phenolic content in the plants as compared to untreated plants. In conclusion, it is suggested that jasmonic acid as an abiotic elicitor could be a promising material used to increase biological activity and pro-health functional value of basil plants.