Objective To study the procalcitonin(PCT)in elderly community-acquired pneumonia(CAP)severity assessed value.Methods 317 cases of community-acquired pneumonia in elderly patients with severe pneumonia group set(111 cases)and ordinary pneumonia group(206 cases),and 67 cases of healthy elderly controls,observed the PCT testing and to study the PCT and PSI,CURB-65 relevance score.Results Severe pneumonia group,ordinary pneumonia group and the normal control group,PCT of the three groups decreased,the difference was statistically significant(P0.05);the levels of PCT in patients with PSI,CURB-65 scores were statistically significant(P0.05);PCT was positively correlated with PSI(r=0.689,P0.05),PCT and CURB-65 score was positively correlated(r=0.511,P0.05),correlation coefficient PSI high.Conclusion PCT can better reflect the severity of patients with CAP,the CAP patients with PCT monitoring of clinical treatment options and prognosis assessment has important clinical value.