Background : It is known that hypertension with type 2 diabetes mellitus increases the risk of arterial stiffness, but it is not clear whether it is accompanied by abnormal oxygenation in the exercising muscle. Methods and results: A total of 50 patients with type 2 diabetes, comprising normotensive patients (n=34, Age:53.6±8.6, BMI:23.0±3.9) and hypertensive patients (n=16, Age:53.9±8.2, BMI:24.5±3.5) , was studied. Right gastronomies muscle oxygenation was measured using near-infrared spectroscopy while resting and in a 210 sec planter flexion exercise. Muscle oxygen utilization rate (%MO2) was calculated as the increasing rate of oxygenated hemoglobin/mymoglobin during a 30 sec arterial occlusion, and reoxygenation time (TR) was calculated after arterial occlusion. The results demonstrated that glycol hemoglobin A1c (HbA1c) and baPWV in hypertensive patients (HbA1c:7.5±1.2%, baPWV:1777.9±320.7 cm/sec) were significantly different from those in normotensive patients (HbA1c:6.7±0.8%, baPWV:1520.2±211.8 cm/sec)(p<0.05, p<0.001), while no difference was observed in %MO2. Moreover, the TR was found to be slower in the hypertensive patients, and showed a positive relationship with the baPWV (r=0.58, p<0.05). From these results, it could be concluded that the arterial stiffness was caused by the decrease of oxygenation and the prolonging of TR in the hypertension with type 2 diabetes patients.