AimsThe beneficial effect of β-blocker on heart failure with reduced ejection fraction is well established. However, its effect on the 1-year outcome of heart failure with mid-range ejection fraction (HFmrEF) remains unclear.Methods and resultsWe analysed the data of the patients with left ventricular ejection fraction (LVEF) between 40% and 49% in China Patient-centred Evaluative Assessment of Cardiac Events Prospective Heart Failure Study (China PEACE 5p-HF Study), in which patients hospitalized for heart failure from 52 Chinese hospitals were recruited from 2016 to 2018. Two primary outcomes were all-cause death and all-cause hospitalization. The associations between β-blocker use at discharge and outcomes were assessed by inverse probability of treatment weighting (IPTW)-weighted Cox regression analyses. To assess consistency, IPTW adjusting medications analyses, multivariable analyses and dose-effect analyses were performed. A total of 1035 HFmrEF patients were included in the analysis. The mean age was 65.5 ± 12.7 years and 377 (36.4%) were female. The median (interquartile range) of LVEF was 44% (42–47%). Six hundred and sixty-one (63.8%) were treated with β-blocker. Patients using β-blocker were younger with better cardiac function, and more likely to use renin–angiotensin system inhibitor and mineralocorticoid receptor antagonist. During the 1-year follow-up, death occurred in 84 (12.7%) treated and 85 (22.7%) untreated patients (P < 0.0001); all-cause hospitalization occurred in 298 (45.1%) treated and 188 (50.3%) untreated patients (P = 0.04). After IPTW-weighted adjustment, β-blocker use was significantly associated with lower risk of all-cause death [hazard ratio (HR): 0.70; 95% confidence interval (CI): 0.51–0.96, P = 0.03], but not with lower all-cause hospitalization (HR, 0.92, 95% CI, 0.76–1.10, P = 0.36). Consistency analyses showed consistent favourable effect of β-blocker on all-cause death, but not on all-cause hospitalization.ConclusionsAmong patients with HFmrEF, β-blocker use was associated with lower risk of all-cause death, but not with lower risk of all-cause hospitalization.