Abstract: OBJECTIVE To investigate the efficacy of moxifloxacin in the treatment of community-acquired pneumonia (CAP) in elderly patients and its effect on pulmonary function. METHODS A total of 126 cases of elderly CAP patients treated in the hospital from Jan. 2014 to Dec. 2016 were selected, and were randomly divided into control group (n=63) and experimental group (n=63). Patients in control group were treated with levofloxacin sequential therapy, and in experimental group were treated with moxifloxacin sequential therapy.Lung function levels were observed in the two groups before and after treatment. The C- reactive protein (CRP), procalcitonin (PCT), periosteum protein and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels of the two groups before and after treatment were determined by enzyme-linked immunosorbent assay, and the clinical curative effect and lung function (pulmonary 1s forced expiratory volume(FEV1), FEV1 percentage of predicted value, and the maximum expiratory flow (PEF)) between the two groups were compared. RESULTS After treatment, the FEV1, FEV1 percentage of predicted value, PEF and FEV1/FVC levels in experimental group were (1.99±0.62)L, (63.25±6.41)%, (59.22±4.61)% and (65.36±6.27)L/min, which were higher than those in control group (P<0.05). After 14d of treatment, the CRP, PCT, periosteum protein and sTREM-1 levels in experimental group were (3.21±0.43)mg/L, (0.11±0.03)μg/ml, (210.12±43.26)μg/L and (41.24±5.46)ng/ml, which were lower than those in control group (P<0.001). There was no significant difference in the incidence of CONCLUSION Moxifloxacin sequential therapy has good efficiency in the treatment of elderly patients with community-acquired pneumonia, which helps to improve pulmonary function, and decrease the levels of inflammatory factors.complications after 4d of treatment between the two groups. After 14d of treatment, the efficiency in experimental group was better than that in control group (P<0.05).