Objective:To investigate the specificity of serum procalcitonin（PCT）

high-sensitivity C-reactive protein（hs-CRP）levels in the diagnosis of bacterial infection

and to explore the feasibility of taking them as index for judging the bacterial infection severity and antibiotic sensitivity. Methods :Hospital patients from July 2013 to July 2015 were selected as the research objects. Patients with negative results from laboratory blood culture and no bacterial infection were taken as control group（group A

20 cases）. A total of 120 patients had lab blood culture and were confirmed to be bacterial infection

including local bacterial infection group（group B

40 cases）

bacterial infection SIRS group（group C

40 cases）and sepsis group（group D

40 cases）. Antibiotics was used in each bacterial infections. Serum PCT

hs-CRP levels before the treatment and 24 hours

4 days

7 days after treatment were detected. Analysis of variance and ROC curve analysis were performed. Results:Single factor analysis of variance showed that there were statistically significant differences in PCT and hs-CRP levels among four groups（F=22.27

P=0.000;F=132.20

P=0.000）. SNK method was used to do multiple comparison and the results showed that the PCT level was higher in group B

group C

group D than in group A（P=0.000）

and there was no statistically significant difference between three infection groups（P >0.05）. There were statistically significant differences in hs-CRP level among A

B

C

D four groups（P=0.000）. Before the use of antimicrobial drugs treatment

the serum PCT level of patients with sepsis was significantly increased;after the bacterial infection being successfully controlled

the patient’s serum PCT level was decreased rapidly

reaching normal levels

while CRP level was declined slowly（P<0.05）.The specificity（87.02%）and sensitivity（80.98%）of serum PCT in the diagnosis of bacterial infectious diseases were higher than those of hs-CRP

with statistically significant differences（P<0.05）. Conclusion:Serum PCT and hs-CRP levels have high specificity in the diagnosis of bacterial infections and have high feasibility as index for judging bacteria infection severity and antibiotics sensitivity

therefore worth clinical promotion.