Abstract: OBJECTIVE To observe the clinical efficacy and application of antibiotic sequential therapy in the treatment of elderly patients with pulmonary infection. METHODS A total of 60 elderly patients with community acquired pneumonia(CAP) from Aug. 2015 to Nov. 2016 were selected as study objects, and were randomly divided into sequential therapy group (30 cases) and continuous intravenous infusion group (30 cases). Patients in continuous intravenous infusion group were given beta-lactam classes (including the second and third generation cephalosporins, semisynthetic penicillins, and beta-lactam plus enzyme inhibitors), macrolides antimicrobial agents (including erythromycin, roxithromycin, and azithromycin), and fluoroquinolones (including ofloxacin and ciprofloxacin). Patients in sequential treatment group were treated with the same type of antimicrobial agents, and given intravenous administration at first, then sequential theray with oral antimicrobial drugs when patiants in stable condition. RESULTS The defervescence time, cough reduction and pulmonary rale reduction in sequential therapy group were (3.62±0.65)d, (3.53±0.51)d, and (3.87±0.73)d, which were lower than (4.28±0.69)d, (4.63±0.82)d, and (4.73±0.87)d in continuous intravenous infusion group, and the difference was statistically significant(P<0.05). The bacterial clearance rate and total effective rate of sequential therapy group were significantly higher than those of continuous intravenous infusion group, and the difference was statistically significant(P<0.05). In addition, the adverse drug reaction rate of sequential therapy group was significantly lower than that of continuous intravenous drip group, and the difference was statistically significant (P< 0.05). CONCLUSION In the term of senile pulmonary infection, antibiotic sequential therapy can not only obtain a better clinical outcome, but also effectively reduce the adverse drug reactions, which is safer and more reliable.