ObjectiveTo investigate the role of dynamic monitoring procalcitonin (PCT) in the comprehensive evaluation during the diagnosis and treatment of community acquired pneumonia (CAP). MethodsFour hundred and sixty-eight patients with CAP were randomly assigned to a PCT-guided group (the research group) and a standard guideline group (the control group). The clinical symptoms,CURB-65 grade,blood leucocyte count and classification,and C-reactive protein (CRP)were compared between two groups. The PCT-guided application time of antibiotics,the hospitalization time,chest CT examination rate,the cure or the improvement rate were also estimated and commpared. ResultsThe hospitalization time [(9.6±1.7)days vs. (10.9±1.6)days],hospitalization cost [(6 957.11±1 009.46) yuan vs. (8 011.35±1 049.77) yuan],chest CT examination rate (56.96% vs. 89.40%),the application time of antibiotics [(16.5±2.3)days vs. (20.0±1.2)days],and the rate of required antibiotics upgrade (6.96% vs. 11.06%) in the research group were all significantly lower than the control group (P<0.05). There was no significant difference between two groups in the ratio of the adverse reaction of antibiotics (14.78% vs. 15.20%),the rate of transfer into ICU (2.61% vs. 3.69%) or the mortality (1.74% vs. 2.30%)(P>0.05). ConclusionOn the basis of CAP guidelines,the dynamic monitoring of PCT may shorten the time of antibiotic use and the hospitalization,reduce the cost of hospitalization and the rate of chest CT scan in patients with CAP.