Abstract: OBJECTIVE Considering the administration intervals to intervene the clinics, the incidence of adverse drug reactions was observed to improve the medication safety of antibiotics injection in outpatients. METHODS With a prospective randomized controlled method, the outpatients using antimicrobial agents, selected from the first central hospital of Tianjin in January—December 2007, were randomly divided into control group and intervention group. The intervention measures of training and education, information collation and dissemination, and administrative supervision were used and analyzed. RESULTS Compared with the control group, the intervention group significantly had more rational administration interval (P<0.01), the incidence of adverse reactions after the intervention was significantly lower(P<0.01). CONCLUSION The intervention effect on the administration interval significantly reduced the incidence of adverse reactions. The intervention was effective.