Abstract: Objective To explore the risk factors of pulmonary hypertension(PAH) in maintenance hemodialysis(MHD) patients and examine the correlations with red cell distribution width(RDW). Methods From January 2015 to December 2018, retrospective analysis was performed for 219 patients undergoing maintenance hemodialysis for >3 months. According to the level of pulmonary artery pressure, they were divided into two groups of pulmonary and non-pulmonary hypertension. Clinical data and laboratory parameters were recorded. Pearson's correlation analysis was utilized for examining the correlation between pulmonary artery pressure and RDW;binary Logistic regression for analyzing the risk factors of pulmonary hypertension in MHD patients. Results There were 124 cases(56. 6%) in pulmonary hypertension group and 95 cases(43. 4%) in non-pulmonary hypertension group. RDW in pulmonary hypertension group was significantly higher than that in non-pulmonary hypertension group(t=-4. 485, P<0. 001). Pulmonary artery pressure was positively correlated with age(r=0. 166), RDW(r=0. 521), high-density lipoprotein(r=0. 150), lg brain natriuretic peptide(lgBNP) (r=0. 375) andleft ventricular mass index(LVMI) (r=0. 268) in MHD patients and was positively correlated with RBC count(r=-0. 211), hemoglobin(Hb) (r=-0. 239), albumin(Alb) (r=-0. 168), triglyceride(r=-0. 199), total cholesterol(r=-0. 233), low-density lipoprotein(r=-0. 224), body mass index(BMI) (r=-0. 145) andejection fraction(EF) (r=-0. 209) were negatively correlated(P<0. 05). The results of binary Logistic regression analysis indicated that systolic blood pressure and RDW were independent risk factors for pulmonary hypertension in MHD patients. Conclusion A significant positive correlation exists between RDW and pulmonary artery pressure in MHD patients. And RDW and systolic blood pressure are independent risk factors for pulmonary hypertension in MHD patients.