OBJECTIVE： To explore the methods and ideas for clinical pharmacists to optimize anti-infective treatment programs in obese patients with pulmonary infection. METHODS： The clinical pharmacist optimized the anti-infection regimen of an obese patient with post-stroke pulmonary infection （BMI＝34.602 kg/m2） admitted to our hospital， and adjusted the dose adjustment and drug replacement of piperacillin tazobactam in the obese patient. And the selection of methicillin-resistant Staphylococcus aureus （MRSA） drugs and dose determination were proposed. RESULTS： According to the patient’s body weight and guidelines， the dose of piperacillin tazobactam was adjusted from 4.5 g， q12 h to 4.5 g， q6 h； the antibiotic was changed to moxifloxacin due to pathogenic changes， the dose was 0.4 g， qd， no need to increase When diagnosed as pneumonia caused by MRSA infection， linezolid was used instead of vancomycin for infection treatment in obese patients， and the dose was determined to be 600 mg， q12 h. The physician adopted the above recommendations. After treatment， the patient’s temperature decreased， cough and sputum eased， and the laboratory indicators returned to normal and discharged smoothly. CONCLUSION： Clinical pharmacists can participate in the drug treatment of special obese patients by exerting their own professional advantages： by adjusting the type， dose and frequency of antibacterial drugs， patients can obtain individualized treatment， improve the safety and effectiveness of patients’ medication， and finally obtain satisfactory results.