Objective To analyze the correlations between diastolic blood pressure and renal function in long-lived elderly living in Zhongxiang City in order to explore an appropriate target value of diastolic blood pressure for them. Methods During January 2013 to March 2019,309 long-lived residents (≥90 years old) in Zhongxiang City were recruited in this study by repetitive face-to-face visits. They were divided into hypertension (HT) group and normal blood pressure (NT) group according to whether they suffered fron hypertension. SPSS statistics 23.0 was used for statistical analysis. Data comparison between two groups was perfomed using Mann-Whitney U test, t test orχ² test depending on data type. The correlation of estimated glomerular filtration rate (eGFR) with clinical indicators was analyzed by Pearson correlation analysis and multiple linear regression model analysis. Further, the diastolic blood pressure was stratified by every 10 mmHg (1 mmHg=0.133 kPa) into 60-70,71-80,81-90,91-100, 101-110 and 111-120 mmHg, and the correlation between diastolic blood pressure stratification and eGFR was analyzed by multiple linear regression. Results These subjects exhibited a high hypertension prevalence of 80.6%(249/309), a low treatment rate of 20.1%(50/249), and an incidence of chronic kidney disease (CKD) of 28.2%(87/309). The HT group had significantly lower urea nitrogen and creatinine levels and CKD prevalence (P<0.05), but significantly higher eGFR and heart disease prevalence (P<0.05) when compared with the NT group. Pearson correlation analysis showed that eGFR was negatively correlated with fasting blood glucose (r=-0.120, P<0.05) and positively with age, diastolic blood pressure and total cholesterol (r=0.160,0.168,0.148; P<0.05). Multiple linear regression analysis indicated that eGFR was positively correlated with age, diastolic blood pressure and total cholesterol (β=0.721,0.238,3.537; P<0.05). With diastolic blood pressure at 60-70 mmHg as the reference, eGFR was increased in the elderly with diastolic blood pressure at 81-90 and 91-100 mmHg. Conclusion The long-lived elderly living in Zhongxiang City have a high hypertension prevalence and a low treatment rate. Good renal blood perfusion could be guaranteed when the diastolic blood pressure is controlled at 81-100 mmHg. The target value of diastolic blood pressure can be appropriately broadened for the long-lived elderly.