Objective To investigate the alteration characteristics and the influencing factors of the circadian rhythm of blood pre-ssure in the senile patients with well-controlled hypertension. Methods A total of 215 consecutive senile patients with hypertension well controlled who were hospitalized in our Department of Geriatrics from January 2016 to March 2017 were enrolled in this study. The 24-hour ambulatory blood pressure monitoring was performed on all patients, and according to their decline rate of nocturnal blood pre-ssure, they were divided into 3 groups:dipper blood pressure group (n=48), non-dipper blood pressure group (n=91) and anti-dipper blood pressure group (n=73). The baseline information, results of ambulatory blood pressure, results of biochemical blood examination, and target organ damage were compared among the 3 groups. SPSS statistics 17.0 was used to perform the statistical analysis. Student’s t test or Chi-square test was employed to analyze different data types. Multiple logistic regression analysis was used to screen the independent risk factors for dipper blood pressure. Results Compared with the dipper blood pressure group, the non-dipper and anti-dipper blood pressure groups had significantly older age [(78.96±6.86) vs (82.59±5.85) vs (75.75±7.43)years], higher body mass index [(25.23±3.57) vs (25.01±3.76) vs (22.43±2.62)kg/m²], higher ratio of patients with cerebrovascular disease history (17.6% vs 35.6% vs 14.6%), and higher nocturnal systolic [(123.04±15.67) vs (137.19±19.11) vs(111.31±12.30)mmHg, 1 mmHg=0.133 kPa] and diastolic blood pressure [(64.88±8.02) vs (69.18±9.76) vs (61.38±7.48)mmHg, all P<0.05]. Creatinine clearance rate (CCr) was obviously lower in the anti-dipper group than the dipper blood pressure group [(48.95±13.86) vs (57.59±12.89)ml/min, P<0.05]. There were more patients having carotid atherosclerotic plagues in the non-dipper and anti-dipper groups than the dipper blood pressure group (90.1% vs 97.3% vs 72.9%, P<0.05). Multiple logisticregression analysis showed that age (95%CI:1.35-5.95, P=0.006), BMI (95%CI:1.43-5.91, P=0.003) and carotid plaque (95%CI:1.25-5.12, P=0.010) were independent risk factors for dipper blood pressure. Conclusion Abnormal circadian rhythm of blood pressure are still seen in the elderly patients with well-controlled hypertension.