Liddle's syndrome was described in 1963 by Liddle, et al., as the disease featuring a hypertension and hypokalemia but with negligible secretion of aldosterone. This syndrome, which morphologically belongs to an abnormal intrinsic tubular disorder with normal renal function, is characterized by hypokalemia, metabolic alkalosis, and hypertension due to the abnormal increase in excretion of potassium in distal tubules or collecting duct and the increase in reabsorption of sodium in distal tubules. This syndrome, which is rare disease, is observed with the low level of plasma and urinary aldosterone and suppressed plasma renin level and is known as dominant mode of inheritance with a family background. The authors paid attention to a 79-year-old man who showed a high blood pressure of 210/130mmHg as well as musle weakness, especially lower extremities due to metabolic alkalosis featuring a hypokalemia level of 2.0mEq/L when he was admitted to our hospital, Because his serum potassium were not improved with the medication of intravenous potassium supply, and his blood pressure continued to be high without the improvement of muscle weakness, we prescribed 300mg of spironolactone for two weeks. His symptom, however, was not cured. Then, instead of spironolactone, we prescribed 150mg of triamterene and a low salt diet which finally improved his symptoms. Because there has been no reported case in the Korean medical literature, we report a case of successfully treated Liddle's syndrome due to triamterene administration.