Abstract: Objective To explore the optimal cut-off point of aldosterone to renin concentration ratio（ARR） for screening primary aldosteronism（PA） in elderly hypertensive patients, and to evaluate effect of ARR combined with aldosterone in improving the screening specificity to reduce risk of confirmatory tests. Methods From March 2016 to March 2019, 65 patients aged 60-80 years old and diagnosed with PA by captopril challenge test or intravenous saline load test at the department of hypertension of Fuwai Hospital were enrolled. In the meantime, 118 age and gender matched patients with essential hypertension（EH） were also enrolled. Plasma renin and aldosterone concentrations were measured by chemiluminescent immunoassay. The receiver operating curve（ROC） of ARR was calculated and used to obtain the best screening cut-off point. The areas under the ROC curve（AUC） of ARR alone and ARR combined with aldosterone were compared. Results The AUC of the ARR was 0.859（95% CI 0.807-0.911）. Youden index was at the highest when the upright ARR cut-off point was set at 4.4（ng/dL）/（mU/L）, of which the sensitivity was 80.0% and the specificity was 78.8%. ARR cut-off at 4.4（ng/dL）/（mU/L） plus aldosterone cut-off point at 15 ng/dL was reasonable, of which the sensitivity was 72.3%, the specificity was 96.6%. When combined ARR with aldosterone for screening PA, AUC was 0.911（95% CI 0.867-0.954）, which was significantly improved compared with the ARR alone（P=0.038）. Conclusions ARR≥4.4（ng/dL）/（mU/L） can be considered as the primary screening cut-off point for elderly patients with PA. Combining upright ARR with aldosterone can improve screening specificity.