Introduction: It has been found that morphological changes of elastic and elastic-muscular arteries wall are the main role in elevation of systolic blood pressure. Furthermore, Isolated systolic hypertension (ISH) has been found that to be associated with cerebral stroke, myocardial infarction and heart failure. And according to national study of prevalence of risk factors on non-communicable disease, it found that risk of CVDs (cardiovascular diseases) is a high among Mongolian and one fifth has more than 3 risk factors of atherosclerosis. The researchers found that atherosclerosis begins relative in young people and endothelial dysfunction is without clinical signs of CVD among Mongolian. Purpose : To determine the atherosclerotic changes and associated with some risk factors of subjects with Isolated systolic hypertension. Materials and Methods: We used hospital-based cross-sectional study design. Data collection was conducted using questionnaire, body measurement, and laboratory methods. A standardized questionnaire was used according to the methodology from the “STEPs” Survey on the prevalence of Non-communicable disease and injury risk factors, body weight, height and blood pressure were measured by standard method. Results : In group with ISH, maximal IMT of CCA was 1.46±0.44mm, systolic diameter was 5.89±0.68mm, diastolic diameter was 6.34±0.73mm respectively which were significantly higher than normotensive group (1.21±0.28mm, 5.58±0.59mm, 5.99±0.58mm) (p<0.05). Furthermore we studied plaques of carotid artery, and atherosclerotic plaques were revealed in 69.2 percent of subjects with ISH which was significantly higher compared with normotensive subjects (p=0.003). And resistive, pulsative and stiffness indexes were significantly higher in group with ISH which represents vascular resistance of CCA. But end-diastolic velocity of CCA significantly reduced in group with ISH (p=0.015). We found that atherosclerotic index increases every year by 6.5 percent, every one mm Hg of systolic blood pressure by 3.7 percent and every year of increasing blood pressure by 10.5 percent respectively. Conclusion
1. Atherosclerotic changes were revealed more in subjects with ISH compared to subjects with normotensive.
2. Advancing age, long duration of smoking, a high level of systolic blood pressure, having a high systolic blood pressure level for a long time and high consumption of salt intake are accelerating atherosclerotic changes of carotid artery.
3. According to increasing atherosclerotic change, blood stream velocity of carotid artery is decreasing and resistive and pulsative indexes are increasing.

Study objective is to determine the mean systolic blood pressure (SBP) and diastolic blood pressure (DPB), prevalence of hypertension (HTN), treatment status, and respective trends in Mongolian population during 2005-2009.Two independent cross-sectional population-based surveys were carried out in 2005 and 2009 to monitor cardiovascular risk factors in men and women aged 15-64 years. The surveys were conducted according to the WHO STEP wise approach.