Abstract: Objective To learn about the status of rational antibacterial drug use and improve the safety, rationality and efficacy of drug use in pharmacy. Methods All unreasonable prescriptions of antibacterial drugs injection in Pharmacy Intravenous Admixture Services (PIVAS) in 2013 were collected, audited, classified and analyzed. Results There were 4 739 unreasonable prescriptions in total, and the major problems were focused on dosage (50.66%), drug solvent (35.24%), solvent quantity (11.84%), incompatibility (2.00%), and inappropriate route of administration (0.26%) and so on. Conclusion Pharmacists can communicate with the doctors in clinical departments through liaison letters and then guarantee the quality drug use for the safety and rationality of patients.