Abstract: OBJECTIVE To analyze the unreasonable prescriptions in pharmacy intravenous admixture services(PIVAS) to ensure patients medication safety. METHODS Clinical pharmacist examined the prescriptions in PIVAS and analyzed the unreasonable prescriptions according to pharmacological knowledge and literatures. RESULTS A total of 155 028 prescriptions was examined, and 816 pieces of unreasonable prescriptions were found, involving problems in improper choice of infusion carriers, unsuitable concentration, incompatibility, improper interval of drug administration and erroneous advising. With the intervention measures method, the rate of irrational prescriptions were reduced from 0.53% to 0.17%. CONCLUSION Examining prescriptions in PIVAS can decrease the irrational administration and improve the safety of patients use of intravenous drugs by the daily work.