Purpose: Wake up time elevated blood pressure was called ���morning surge��� and wake up time regarded as dangerous time zone for 24 hours. Pulse pressure (PP) has been known to be a mechanical property of large arteries, elevated PP was tended to be association of target organ damage. But ambulatory PP does not have a well-known prognostic value in hypertensive patients. The purpose of this study is to identify the usefulness of ambulatory PP monitoring and wake up time pulse PP is more dangerous than the other time. Methods: A total of 388 hypertensive patients (53.3짹14.8 years, 55.5% males) were performed 24 ambulatory blood and PP monitoring. We compared the relation with left ventricular hypertrophy (LVH) and 24 hour mean, day time, night time and wake up time PP respectively. Results: Average 24 hour PP was 48.0짹8.6mmHg. Day time mean PP was 48.4 짹 8.2mmHg and night time PP was 46.2짹 8.9mmHg. Wake up time PP was 45.3짹 9.3mmHg. Differ from blood pressure pattern, nocturnal fall was slightly observed morning surge was not seen in pulse pressure. 24 hour, day and night PP were negatively correlated with age. 24 h PP (r=0.143, p=0.005), day PP (r=0.144, p=0.005) and night PP (r=0.144, p=0.005) were significantly related with left ventricular hypertrophy. Wake up time PP were no significant relation with LVH. Conclusion: Day and night time PP were more closely related with LVH than Wake up time PP in the patient with hypertension. Ambulatory PP monitoring may give us useful information for target organ damage in the patient with hypertension.