Objective To explore the relationship between resting heart rate and long-term prognosis of patients with connective tissue disease-associated pulmonary arterial hypertension. Methods 89 patients with CTD-PAH diagnosed by right cardiac catheterization were collected from the Departments of Rheumatology, Jiangsu Province Hospital and Nanjing Medical University First Affiliated Hospital 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 and analyzed. Kaplan-Meier and COX methods were used for survival analysis. Results There was no significant difference in sex, age, WHO-FC, 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 <0.001). The overall 1-, 3-and 5-year survival rates of patients with resting heart rate <100 beats/min and ≥100 beats/min were98.6%、90.7%、87.6% vs 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.