Abstract: Objective To compare the therapeutic effect and safety of linezolid and vancomycin on hospital-acquired pneumonia caused by Gram-positive bacteria in aged patients. Methods Clinical data about 51 patients with hospital-acquired pneumonia treated with linezolid and 43 patients with hospital-acquired pneumonia treated with vancomycin were retrospectively analyzed.Therapeutic efficiency,bacterial clearance and adverse effects of linezolid and vancomycin for hospital-aquired pneumonia were compared. Results All the pathogens were sensitive to linezolid and vancomycin.The clinical efficacy of linezolid and vancomycin was 72.5% and 53.5% respectively for hospital-acquired pneumonia（P＞0.05）,and was 76.5% and 50% respectively for MRSA pneumonia（P＜0.05）,with a pathogen clearance rate of 68.6% and 62.8%,respectively（P＞0.05）.No statistical difference was found in adverse events of the two drugs.However,the tolerance of patients was better to linezolid than to vancomycin. Conclusion The therapeutic effect of linezolid is better than that of vancomycin and the tolerance of patients is also better to linezolid than to vancomycin.