Frankincense is an oleo-gum-resin obtained from Boswellia trees. In this study, Boswellia serrate essential oil was extracted by Clevenger apparatus, then segregation and recognition of components was performed by Gas chromatography-mass spectrometry (GC-MS) methods. The follin-ciocalteu method was used for estimating total phenol content and the antioxidant activity was evaluated by several methods including, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, total antioxidant capacity, reducing power, and rancimat test in different concentrations (100-1000 ppm). Components identification revealed that ?-pinene (29.8%), a-thujene (5.92%), b-Pinen (3.41%) and pcymene (3.16%) had the highest percentage in the essential oil, and the total phenolic content was 94.88 mg GAE equivalents/100g of essential oil. The antioxidant activity of essential oil was dosedependent in all tests and the highest inhibition of DPPH radicals, reducing power and total antioxidant capacity was detected at a concentration of 1000 ppm, which were 22.23%, 0.65 and 1.18, respectively. In rancimat test, the highest oxidative stability of the oil was also recorded for concentration of 1000 ppm of the essential oil. Results of the present study demonstrated that Boswellia serrata essential oil could be used as a potential source of natural antioxidants for oil and oil-containing foods.