Abstract: Objective To explore the significance of serum procalcitonin (PCT) abnormal level for the diagnosis of infection in patients with heart failure,and provide reliable evidence for the infection treatment. Methods Ninety patients with heart failure were randomly selected from our hospital and were divided into infection group and non-infection group,with 45 cases in each group.Serum PCT levels in two groups were detected and the sensitivity,specificity and positive predictive value of PCT detection were compared. Results Serum PCT level in the infection group (10.34±2.64) ng/ml was significantly higher than non-infected group (0.23±0.05) ng/ml before the treatment (P<0.05).There was no significant difference in serum PCT levels between two groups after the treatment (P>0.05).Infection diagnosis sensitivity (91.11%),specificity (95.56%),positive predictive value (88.89%) in the infected patients were significantly higher than non-infected patients (48.89%,55.56%,62.22%),P<0.05. Conclusion Serum PCT detection exerts obvious effect for the infection diagnosis of heart failure patients and produces high PCT level in the infected patients,which indicates the possibility of infection and needs active measures.This detection has a high sensitivity,accuracy and positive predictive,so it is of great clinical significance.