OBJECTIVE： To reduce the dispensing errors of similar drugs in hospital outpatient pharmacy， and realize the drug traceability. METHODS： Based on adding drug electronic regulatory code field in drug dictionary background database of hospital information system （HIS），  prescription dispensing process in outpatient pharmacy of our hospital was improved. Drug electronic regulatory code was added for scanning code review before secondary review dispensing，  and drug terminal traceability was realized based on it. Through comparing the dispensing outing error rate before and after 12 months of improvement，  ratio of “special abnormal data” related with dispensing error of similar drugs in checking，  patients’ waiting time and other indicators，  the prescription dispensing quality of outpatient pharmacy before and after improvement was evaluated. RESULTS： After adding drug electronic regulatory code for scanning code review，  the dispensing outing error of similar drugs was decreased from 22 cases to 1 case （accounting for 0.019 7‰，  0.010 3‰，  respectively），  number of “special abnormal data” was decreased from 836 to 436 （accounting for 31.5％，  16.8％，  respectively），  and the average waiting time of patients had no obvious extension （10.85 min，  10.88 min，  respectively）. It had achieved the traceability inquiry of most outpatient drugs from the pharmacy to the patients. CONCLUSIONS： The drug electronic regulatory code can reduce the dispensing outing error of similar drugs in outpatient pharmacy，  which is conducive to the establishment of drug traceability chain and has improved the quality of pharmaceutical care.