The antioxidant activity of parsley extract obtained by ultrasonic-assisted extraction method was evaluated using DPPH radical scavenging method. A high content of total polyphenols (50.82±1.8mg gallic acid equivalent) GAE(/g dried parsley powder), total flavonoids (42.6±1.2 mg quercetin/g dried parsley powder), apigenin (9.48±0.11 mg/g dried parsley powder), and antioxidant activity (27±0.9% at 100 ppm) were quantified in parsley leaves.The extract was purified by column chromatographymethod, and the apigenin purity was determined to be 86% using the HPLC method. The antioxidant activity of the unpurified and purified extracts containing the same amount of apigenin was 39.7±0.9 and 38.1±0.4%, respectively. This indicates that the antioxidant properties of the parsley leave extract were mostly attributed to the presence of apigenin whose antioxidant activity was well demonstrated.