Objective To promote rational use of traditional Chinese medicine ( TCM ) decoction pieces by rational drug use monitoring sys-tem.Methods Adopting rule builder system of clinical rational drug use system to build rational use TCM decoction pieces rules.The prescription quality of TCM decoction pieces will be placed in the four stages of PDCA cycle.By means of prescription analysis ( P ) to find the problem , rule builder(D) to carry out problem, prescription intervention(C) to check problem, prescription comment(A) to summarize problem.The prescrip-tion quality continuous improvement with cycling continuously of PDCA.Results Intervention of alertting , warning and intercepting through the doctor ’ s prescribed interface , the number of irrational TCM decoction pieces prescriptions dropped from 6.91%to 5.35%after intervening ,but the overdose prescriptions are still widespread.Conclusion The comment and intervention system of TCM decoction pieces prescriptions based on in-telligence inference engine obviously improved the prescription quality.It can be widyly used in TCM decoction pieces prescriptions quality management.