Objective To explore the influence of baseline blood pressure on the long-term development of frailty in community-dwelling older adults with hypertension to provide a basis for scientific blood pressure management of elderly hypertension patients. Methods The elderly non-frailty hypertension patients who had complete sociodemographic data and results of comprehensive geriatric assessment in a community in Beijing from January to June 2019 were subjected in this study, and they were followed up by telephone from January 1 to February 14,2023. Finally, 372 elderly hypertension patients were enrolled in this study. FRAIL scale was used to evaluate frailty in the follow-up, and those with the score ≥3 points were classified as frailty. Binomial logistic regression analysis (input method) was adopted to calculate the OR and 95%CI between baseline blood pressure level and long-term occurrence of frailty. The dose-response relationship between the baseline level and the occurrence was analyzed by generalized additive model using smooth curve fitting and threshold effect analysis. Empower Stats and SPSS 25.0 were used for statistical analysis. Data comparison between two groups was performed using student′s t test, Mann-Whitney U test or Chi-square test depending on data type. Results Multivariate adjusted logistic regression analysis showed that baseline systolic and diastolic blood pressure levels were not significantly correlated with occurrence of frailty, while baseline pulse pressure was negatively with the occurrence (OR=0.983, 95%CI 0.968-0.998; P<0.05). Smooth curve fitting and threshold effect analysis indicated that the relationship between baseline systolic blood pressure level and frailty was U-shaped, with an inflection point of the U-shaped curve of 140 mmHg(1 mmHg=0.133 kPa). When systolic blood pressure <140 mmHg, the OR (95%CI) was 0.957 (0.925-0.990; P<0.05), and when systolic blood pressure >140 mmHg, the OR (95%CI) was 1.006 (0.985-1.028; P>0.05).Conclusion In community-dwelling older adults with hypertension, baseline systolic blood pressure level has a long-term effect on occurrence of frailty, in a U-shaped relationship, with an inflection point of 140 mmHg.