Clove has been frequently used as anti-diabetic, anti-microbial, anti-inflammatory, anesthetic drug and remedies for stomachache by coldness. In this study, the antioxidant activity of extract from Clove was studied in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on Cu<SUP>2+</SUP>-induced human LDL oxidation. Anti-platelet aggregation and anti-thrombotic effects of Clove extracts were studied ex vivo methods by mesuring the inhibitory effect on thrombin induced platelet aggregation and the fibrinolytic activity. The Clove extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation in vitro. Moreover Clove extracts were exhibited remarkable inhibitory effect on platelet aggregation and fibrinolytic activity. In conclusion, the Clove extracts have anti-oxidative and anti-atherosclerotic effects in vitro and ex vivo system, which can be used for developing pharmaceutical drug against oxidative stress and atherosclerosis.