Background: Metabolic syndrome is high prevalence of cardiovascular disease(CVD), related to formation of small dense low-density-lipoprotein (sdLDL). Hypertension is one of components of metabolic syndrome. But, association of hypertension and sdLDL is not well known in non-metabolic syndrome patients. Methods: A total of 367 non-metabolic syndrome patients were enrolled. 230 were hypertensive(group A) and 137 were normotensive subjects(group B). To exclude metabolic effect of lipoprotein, the patients with hypertriglyceridemia and diabetes were excluded. We measured LDL peak particle diameter and peak size of LDL by gradient gel electrophoresis. Pattern A(70 pts) and pattern B (dominant small dense LDL, 8pts) were defined as a diameter of >25.5 nm and ���25.5 nm, respectively Results: Comparing with group B, percentage of sdLDL was higher in group A (38.1% vs 40.3%, p=0.038).(Table1) Plasma total cholesterol, LDL-cholesterol, LDL cholesterol apo B, HDL-cholesterol, triglyceride, free fatty acids, sdLDL and apolipoprotein(A1, B, CII and E) levels were not different between two groups. Peak particle diameter and peak size of LDL were similar in both group.(Table 1) The BMI, HOMA index, and CRP were not different between the two groups. The portion of pattern A and B in group A and group B were not different.(A, n=184(80%) vs n=108(78%) ; B, n=27(11.4%) vs n=7(7.3%), P=0.116) Conclusions: In non-metabolic syndrome patients, presence of hypertension was significantly correlated with percentage of sdLDL. This means that mechanism of sdLDL formation in hypertension is different that of metabolic syndrome and that hypertensive patients without metabolic syndrome may also have higher risk of atherosclerotic disease due to sdLDL.