Objective:To explore the relationship between resting heart rate and long-term prognosis of patients with connective tissue disease-associated pulmonary arterial hypertension(CTD-PAH). Methods:A total of 89 patients with CTD-PAH diagnosed by right cardiac catheterization were collected from the Departments of Rheumatology,the First Affiliated Hospital of Nanjing Medical University from 2009 to 2021. The clinical characteristics,two-dimensional echocardiographic parameters,hemodynamic parameters and survival of patients with heart rate < 100 beats/min and heart rate ≥100 beats/min were compared. Kaplan-Meier and Cox methods were used for survival analysis. Results:There was no significant difference in sex,age,WHO functional class,6-minute walking distance,N-terminal pro-brain natriuretic peptide,two-dimensional echocardiographic and hemodynamic parameters between the two groups. The mortality of patients with resting heart rate ≥100 beats/min was higher than that of patients with resting heart rate <100 beats/min(P < 0.01). The overall 1-,3- and 5-year survival rates of patients with resting heart rate < 100 beats/min and ≥ 100 beats/min were 98.6%,90.7%,87.6% and 93.8%,66.8%,55.6%. After adjustment for age and sex, resting heart rate ≥100 beats/min remained an independent risk factor for prognosis of patients with CTD-PAH. Conclusion:The resting heart rate may be one of the indexes to predict the long-term poor prognosis of patients with CTD-PAH and may reflect the overall function of the right ventricle.