Abstract: OBJECTIVE To investigate the changes and clinical significance of serum adiponectin and leptin in elderly patients with bacterial pneumonia. METHODS A total of 70 elderly patients with bacterial pneumonia treated in Xuzhou First People’s Hospital from Oct. 2017 to Mar. 2018 and 50 healthy people who underwent physical examination were selected as the research subjects, of which 34 patients with severe pneumonia were assigned to group A, 36 patients with ordinary pneumonia were assigned to group B, and 50 healthy persons were assigned to group C. The serum adiponectin and leptin, procalcitonin（PCT） and C-reactive protein（CRP） of the three groups were compared. RESULTS A total of 90 pathogens were cultured from the sputum samples of patients in group A and group B, among which 56 Gram-negative bacteria accounted for 62.22%, and 34 Gram-positive bacteria accounted for 37.78%. The differences in the concentration data of adiponectin, leptin, CRP, and PCT among the three groups were significant（P＜0.05）. The concentration of adiponectin was（4.78±1.84） mg/L in group A, significantly lower than that in group B（6.72±1.69 mg/L）, and group B was significantly lower than group C（P＜0.05）. Leptin, CRP, and PCT in Group A were（17.48±4.20） μg/L,（89.32±23.00） μg/L,（4.02±2.21） μg/L, respectively, significantly higher than those in Group B（12.96±2.09） μg/L,（70.34±26.74）μg/L, and（3.50±1.85） μg/L, respectively, and group B was significantly higher than group C（P＜0.05）. In the data of the three groups of patients, adiponectin was negatively correlated with leptin, CRP, and PCT（r=-0.321,-0.251,-0.304, P＜0.001）, and leptin was positively correlated withCRP and PCT（r=0.354, 0.384, P＜0.001）, and there was a positive correlation between CRP and PCT（r=0.332, P＜0.001）. Adiponectin, leptin, CRP, and PCT were used to diagnose patients in group A and B. The optimal cutoff values were 5.74（mg/L）, 15.44（μg/L）, 75.59（μg/L）, and 3.13（ μg/L）, and the Yoden index was 48.37%, 65.36%, 43.14%, 17.65%, respectively. CONCLUSION Serum adiponectin and leptin had a certain indicating effect on the severity of the elderly patients with bacterial pneumonia. However, there were many influencing factors in the actual clinical work, and the situation was more complicated. The patient’s situation should be comprehensively considered under the indicators.