OBJECTIVE： To explore the construction effect of rational drug use monitoring system on the improvement of clinical drug use in the hospital. METHODS： The data about the construction of rational drug use monitoring system were collected from our hospital， including pharmacist workstation prescription check （check before prescription/medical order charging to realize warning in advance），clinical pharmacy management system prescription comment （realize prescription/medical order comment afterwards） and adverse drug reaction/adverse drug event （ADR） reporting  information platform （realize online ADR reporting） during 2014-2015. The data was analyzed to evaluate the effectiveness of system construction. RESULTS & CONCLUSIONS： There were a total of 3 417 329 prescriptions audited by the pharmacist workstation within 2 years through improving system functions， including 7 315 prescriptions were returned to doctors to be modified， the percentage of which declined from 0.39％ to 0.08％. The pass rate of prescription comment pre-judgment increased from 81.2％ to 90.4％ in 2015 by clinical pharmacy management system. The valid case number of ADR monitoring and reporting increased from 186 cases to 267 cases， involving all department of our hospital. The construction of rational drug use monitoring system in our hospital can improve the standardization of prescription/medical orders， the level of rational drug use and the case number of ADR， which has achieved the expected results.