OBJECTIVE： To improve work efficiency and quality of pharmacy intravenous admixture services （PIVAS）. METHODS： The information system of PIVAS in our hospital was optimized. The effects of the system were evaluated by comparing indexes 6 months before and after optimization. RESULTS： Compared with before optimization， the function of automatic repeated medical order checking was added to reduce the workload of manual prescription checking in respect of medical order checking； various batch generation rules were set up to reduce the number of adjusted batch by hand in respect of batch arrangement； label number and signature function were added to realize the information traceability function in respect of label printing and signature； rapid inquiry of transfusion state was realized by using two dimensional code scanning technology in respect of preparation scanning. When the daily workload increased and the staff did not increase， the number of daily manual checked medical orders were 956 before optimization and 257 after optimization； the time of daily labeling and dispensing were 180 min before optimization and 135 min after optimization； the number of monthly delivery error were 3.6 before optimization and 2.5 after optimization. CONCLUSIONS： Optimized function of information system can improve the work efficiency and work quality of PIVAS.