Case: The case is 86-year-old male hypertensive patient with anti-hypertensive drug for 5 years. He has been provided Amlodipine besilate 5mg at 0800h and doxazosin mesylate 2mg at 2300h for long. In June 2020, he noticed unstable fluctuation of Blood Pressure (BP) during morning, afternoon and night. Results: Then, he checked the circadian rhythm of BP, which showed higher BP in early morning, decreasing BP 0800-1000h, minimum BP during 1000-1400h, increasing BP during 1400-1800h and stable BP during 1800-2400h. Due to the result, he changed to take amlodipine at 2300h. Consequently, his BP gradually became stable during 24 hours after 2 weeks. Discussion: Some factors may exist for contributing improved BP fluctuation. They include a) pathophysiological characteristics of BP circadian rhythm, b) effective time for anti-hypertensive drug, c) accuracy of the obtained BP data and d) the social and psychological reliability of the patient. Regarding d) he was engaged in research and development work as a senior researcher at a chemical company. He has been also a member of New Elderly Association (NEA), which was established by Shigeaki Hinohara. He lives on the philosophy of Hinohara-ism for long, associated with stable mind and body.