ObjectiveTo explore intervention efficacy of clinical application of antimicrobial agents in internal medicine departments of a hospital. Methods1 880 medical records from internal medicine and pediatrics departments this hospital in JulyDecember 2010 were randomly selected as control group (before intervention), and  2 207 medical records in JulyDecember 2011 were as trial group (after intervention), antimicrobial use of two groups was compared. ResultsThe overall usage rate of antimicrobial agents after intervention was lower than before  intervention (48.12% vs  58.62%, χ2=44.45，P＜0.001）. Except endocrinology, pediatrics  and  hematology departments, the usage rates of antimicrobial agents in the other departments after intervention were all obviously lower than before  intervention（all P＜0.05）. The usage rate of antimicrobial agents in endocrinology and  hematology departments were both low（＜40%）, which met the requirements of Ministry of Health.ConclusionComprehensive intervention in clinical use of antimicrobial agents reduced the usage rate of antimicrobial agents in internal medicine and pediatrics departments in this hospital.