Objective To investigate the clinical significance of serun procalcitonin (PCT) and adrenomedullin(ADM) levels in elderly patients with pneumonia diagnosis.Methods Thirty-eight elderly patients with pneumonia who were admitted to our hospital were collected as the study group.Thirty-two cases of non-pneumonic patients hospitalized in respiratory department at the same period for lung tumor,non-infective interstitial lung diseases and pulmonary edema were chosen as the control group.According to CURB-65 score,the study group was divided into three subgroups as mild,moderate and severe group.Levels of serum PCT and ADM at the 1st day,3rd day and 7th day were measured by ELISA,and data were statistically analyzed.Results Serum PCT ((1.98 ± 0.32) μg/L vs.(1.63 ± 0.44) μg/L,t =3.989,P =0.040) and ADM levels ((0.92±0.31) μg/L vs.(0.52±0.12) μg/L,t =5.987,P ＜0.001) on the first day of the treatment was significantly higher than in the control group.Serum PCT and ADM levels in the three subgroups decreased after treatment,and at each time point serum PCT (1st day:(2.19 ±:0.36) μg/L vs.(1.80 ± 0.28) μg/L vs.(1.83 ±0.22) μg/L;3rd day:(2.08 ±0.34) μg/L vs.(1.73 ±0.35) μg/L vs.(1.75 ±0.24) μg/L;7th day:(2.05 ±0.32) μg/L vs.(1.65 ±0.30) μg/L vs.(1.61 ±0.31) μg/L) and ADM levels (1st day:(1.08 ± 0.31) μg/L vs.(0.80 ± 0.25) μg/L vs.(0.77 ± 0.22) μg/L; 3rd day:(1.09 ± 0.32) μg/L vs.(0.77 ±0.23) μg/L vs.(0.75 ±0.21) μg/L;7th day:(1.08 ±0.33) μg/L vs.(0.66 ±0.18) μg/L vs.(0.72 ±0.25) μg/L) in the severe group were significantly higher than in the other two subgroups (P ＜0.05).Serum PCT and ADM levels in survived patients on the 1 st day,3rd day,and 7th day after treatment were significantly lower than in patients who were deceased (PCT:1 st day:(1.82 ± 0.26) μg/L vs.(2.16 ± 0.37)μg/L;3rd day:(1.74 ± 0.29) ~L vs.(2.06 ±0.31) μg/L;7th day:(1.62 ± 0.30) μg/L vs.(2.03 ±0.30) μg/L;P ＜0.05 ;ADM:1st day:(0.78 ± 0.23) μg/L vs.(1.06 ± 0.29) μg/L;3rd day:(076 ± 0.21)μg/L vs.(1.08 ± 0.30) μg/L; 7 th day:(0.70 ± 0.20) μg/L vs.(1.09 ± 0.35) μg/L; P ＜ 0.05),and serum PCT and ADM levels did not change significantly in deceased patients after treatment.Conclusion Serum PCT and ADM levels can serve as serum markers in early diagnosis,the severity of pneumonia and estimating prognosis in elderly patients.