Objective To investigate the clinical significance of red blood cell distribution width in the early diagnosis of patients with chronic heart failure.Methods Seventy eight cases of chronic heart failure patients from November 2011 to November 2013 in our hospital were recruited in this study,and were divided into three different heart failure groups (Ⅱ,Ⅲ,and Ⅳ) according to the degree of heart failure; 40 healthy cases were used as control group.The red blood cell distribution width was measured among four groups.The relationship of the red blood cell distribution width and chronic heart failure was analyzed.According to the red blood cell distribution width data,patients were grouped into ＜ 13.1％,13.1％ ～ 14.5％,and ＞ 14.5％ groups.The eventual fatality rates were compared among three groups with different red blood cell distribution width.Results (1) The red blood cell distribution width was (11.63 ±0.71)％,(13.11 ±1.08)％,(14.31 ±1.52)％,and (16.83 ±0.71)％ in the healthy group,andⅡ,Ⅲ,and Ⅳ heart failure groups,respectively.The red blood cell distribution width was gradually increased with the degree of heart failure,with a statistically significant difference among four groups (P ＜ 0.05).(2) The mortality was 0 (0/32),14.8％ (4/29),and 41.2％ (7/ 17) in different red blood cell distribution width groups (＜ 13.1％,13.1％ ～ 14.5％,and ＞ 14.5％),respectively.The mortality was gradually increased with the increased red blood cell distribution width,with a statistically significant difference among three groups (P ＜ 0.05).Conclusions Red blood cell distribution width is of great importance to detect disease degree of chronic heart failure and can guide one to effectively evaluate disease processes and therapeutic effect.