OBJECTIVE： To perfect the rational medication checking system in PIVAS of our hospital， and strengthen the accuracy of rationality checking so as to improve work efficiency. METHODS： Many imperfections of the system in our hospital were discovered and improved， and related index were compared statistically 3 months before and after function improvement. RESULTS & CONCLUSIONS： Considering about the imperfections， such as “questionable medical orders” cannot be fed back effectively； new and old medical orders， checked and unchecked medical order， cancelled and normal medical orders cannot be distinguished clearly and checked， the function of medical order withheld， multiple screening and inquiry are added into the system. After the application of new function， the number of daily checked orders per capita increased （96.5 groups vs. 144.8 groups）， while the decrease was found in the number of daily refund orders （158.3 groups vs. 47.6 groups）， daily missed orders （0.32 groups vs. 0 group）， daily redundant packaged drug orders （2.1 groups vs. 0 group） and the time of cancelling and refusing orders （15 min vs. 0.028 min）， etc. Operation procedure of medical order checking becomes more easy and convenient， improves the accuracy and   efficiency and avoids the implementation of irrational medical orders.