ObjectiveTo evaluate the clinical significance of serum procalcitonin (PCT) in early diagnosis of pulmonary tuberculosis (PTB) complicated with pulmonary infection. MethodsClinical data of active PTB patients admitted to a hospital between August and December 2013 were collected, patients were divided into bacterial infection group(n=104), fungal infection group(n=37) and control group (n=95) according to whether patients were associated with bacterial infection, fungal infection, and without infection, serum PCT concentrations in three groups were compared, receiver operating characteristic (ROC) curve analysis was conducted. ResultsThe median PCT concentrations in bacterial infection and fungal infection group was 0.44ng/mL and 0.30ng/mL respectively，which was significantly higher than 0.16ng/mL of control group（Z=9.49，3.51 respectively，both P<0.001）. The area under curve (AUC) was 0.89（0.84-0.93）and 0.69（0.61-0.77）respectively; cutoff point was 0.31 ng/mL and 0.27 ng/mL respectively; sensitivity was 79.81%（70.57%-86.80%）and 59.46%（42.19%-74.80%） respectively; specificity was 83.16%（73.79%-89.78%） and 73.68%（63.48%-81.95%）respectively.ConclusionPCT level is a valuable predictor for early diagnosis of PTB complicated with pulmonary infection, and can provide reference for the rational use of antimicrobial agents.