Several studies suggested that beta-glucan may have a cardioprotective role against developing high blood pressure (BP). The current study investigated the underlying mechanism of beta glycan as antihypertensive and its effect on vascular functions in males.A total of 20 adult male Wistar rats weighing 180-200 g were divided into 2 groups 10 per each. Group I: Control group were fed standard rat chow for 15 weeks. Group II: Beta glycan fed group in the form of oat cereals by gavage(305 mg per kg body weight per day) for a period of 15 weeks. Rats of both groups were subjected to blood pressure measurement at 0, 10, 15 weeks. Blood samples were collected for measurement of plasma catalase, plasma MDA, lipid profile. Aortic tissue was excised to study vascular reactivity and measurement of aortic tissue nitrate.Significant reduction in the systolic & diastolic blood pressure in beta glycan fed group. This was accompanied by significant increase in plasma catalase & aortic tissue nitrate while plasma MDA, TC, TAG , LDL & atherogenic index were significantly decreased. Significant decrease in the contractile response of aorta to phenylephrine with significant increase in the relaxing response to acetylcholine in the beta glycan fed ones. Beta glycan is a beneficial antihypertensive vasorelaxing agent that is recommended to be added to the diet especially in males to balance the pro- atherogenic effect of testosterone. This cardioprotective role is achieved through decreasing the oxidative stress, triglycerides and total cholesterol level. Inaddition, the aortic tissue nitrate was significantly increased