Abstract: Objective To investigate the relationship between the red blood cell distribution width (RDW) with non-invasive hemodynamic monitoring and body composition in peritoneal dialysis (PD) patients, and its applied value in PD patients.Methods Forty-four hospitalized PD patients were retrospectively reviewed, and 30 cases of healthy people served as a control group. The clinical characteristics and parameters such as RDW, brain natriuretic peptide (BNP), N-terminal brain natriuretic peptide (NT-proBNP), non-invasive hemodynamics and body composition were collected. The differences between two groups and the relationship between RDW and other parameters were analyzed.Results The RDW, BNP, and NT-proBNP in PD group were significantly higher than in the control group with the difference being statistically significant (P<0.01). ECW/TBW was significantly higher, and body fat mass, body mass index, percent body fat, visceral fat area and body-hip ratio were significantly lower in PD group than those in the control group (P<0.05). RDW in PD group was positively correlated with BNP and NT-proBNP (r₁=0.417, r₂=0.396; P<0.01), and BNP was positively correlated with NT-proBNP (r=0.891, P<0.01). RDW was positively correlated with HR and STR (r₁=0.343, r₂=0.364, P<0.05), and negatively with CI, SV, SI, EF, VI (r₁=-0.277, r₂=-0.399, r₃=-0.437, r₄=-0.335, r₅=-0.338; P<0.05). In PD group RDW was positively correlated with ECW/TBW (r₁=0.300, P<0.05). Multivariate linear regression method showed that RDW was associated with ECW/TBW (t=2.03, P<0.05).Conclusions RDW can be used as a predictor of poor prognosis in PD patients, and NT-proBNP can be used to assess the cardiac function in dialysis patients instead of BNP.