OBJECTIVE: To prepare Yizhi Mixture and establish a method for its quality control. METHODS: The mixture was prepared by water decoction method,Radix Polygalae,Cortex Phellodendri,and Radix et Rhizoma Glycyrrhizae uralensis Fisch.in the mixture were identified qualitatively by TLC. The contents of trace amount of paeoniflorin in Yizhi mixture was determined by HPLC. RESULTS: The studies on the quality control showed that the characteristics for identification by TLC were distinct. The linear range of peoniflorin was 0.25～10 mg?L-1.The average recovery was 99.06% and its RSD was 4.91%(n=5).CONCLUSION: The mixture is reasonable in formula and simple in preparation technology. A quality standard has been established for the mixture. The methods for identification and quantification were simple, reliable and practical.