Objective To investigate the relationship between red blood cell distribution width (RDW) and cardiac systolic function in patients with chronic Heart Failure (CHF) and its mechanism. Methods A total of 136 patients with chronic heart failure hospitalized in the department of cardiovascular medicine of Fenyang hospital from September 2016 to May 2018 were divided into three groups: low RDW group (<13.2%, 43 cases), middle RDW group (<13.2% to 14.5%, 47 cases) and high RDW group (>14.5%, 46 cases). The noninvasive cardiac hemodynamic parameters were compared among the three groups, and the activity of Na+-K+- ATPase and Ca2+-Mg2+-ATPase in erythrocyte membrane were compared. Results Hemoglobin in high RDW group was lower than that in low RDW group (P < 0.05), and the level of log NT proBNP in high RDW group was higher than that in low RDW group (P < 0.05). The left ventricular ejection fraction (LVEF), cardiac output (CO), cardiac index (CI), systolic index, left ventricular work per minute and work per beat index in the high RDW group were lower than those in the middle RDW group (P < 0.05), and those in the middle RDW group were lower than those in the low RDW group (P < 0.05). The activity of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in the high RDW group was lower than that in the middle RDW group (P < 0.05), and that in the middle RDW group was lower than that in the low RDW group (P < 0.05).Pearson linear correlation analysis showed that RDW in CHF patients was negatively correlated with LVEF (r = -0.3551), SV (r = -0.1841), CO (r = -0.2640), CI (r = -0.2763), AMPC (r = -0.2437), IC (r = -0.2669), HI (r = -0.2213), SW (r = -0.1987), CW (r = -0.2975) and CWI (r = -0.3156) (all P < 0.05); RDW was negatively correlated with the activity of Na+-K+-ATPase (r = -0.8216) and Ca2+-Mg2+-ATPase (r = -0.7366) of erythrocyte membrane (all P < 0.05). Conclusions The hemodynamic parameters of CHF patients were negatively correlated with RDW. The decrease of Na+-K+- ATPase and Ca2+-Mg2+-ATPase activity in erythrocyte membrane may be one of the reasons.