OBJECTIVE： To provide reference for effective drug cost control. METHODS： The data of prescription was collected from district A of a three-level hospital during Jul. 2013 to Mar. 2014 （before intervention） and Apr. to Dec. 2014 （after intervention）， and then compared statistically in respects of outpatient and inpatient drug cost per time， outpatient and inpatient drug ratio， drug cost per time of each inpatient department， average number of drug types in some inpatient department and cost of key intervention drugs before and after intervention. RESULTS： The outpatient and inpatient drug cost per time were decreased significantly after intervention， decreasing by 11.22％ and 17.39％， respectively. The outpatient and inpatient drug ratio were decreased significantly， decreasing by 5.92％ and 21.17％， respectively. Drug cost per time of 20 inpatient departments were decreased significantly， decreasing by 33.04％. Average number of drug types in the inpatients of nephrology department， cardiovascular medicine department， tumor hematology department， cholelithiasis surgery department and thoracic surgery department were decreased by 2.91， 3.03， 5.94， 5.55， 4.22 types， respectively. The cost of drugs with high contribution rate were decreased significantly. CONCLUSIONS： The district A of the hospital effectively controls drug cost， reduces the number of drug types and decreases the cost of adjuvant drugs in prescription so as to optimize the structure of drug use.