Abstract: OBJECTIVE To investigate the stability of Bazhen Yizhi mixture and to develop a quantitative analysis of simultaneous determination of liquiritin, liquiritin apioside and hesperidin by single-marker method. METHODS The analysis of this mixture was performed on HPLC-DAD and by using hesperidin as a standard reference, the relative correction factors(RCFs) and relative retention time of the other two constituents were measured and calculated. Moreover, comparison of the difference between the quantitative analysis of multicomponents by single marker(QAMS) and external standard method(ESM) was used to explore the feasibility of QAMS. Meanwhile, the stability of Bazhen Yizhi mixture was investigated under high temperature, bright lights, acceleration and long-term room temperature test conditions for its storage conditions and expiration dating to provide data. RESULTS By methodological study, three constituents showed good linear relationships within 4.512-108.2, 10.13-101.30, 4.496-107.90 μg·mL^-1(r>0.999), whose average recoveries were 95.9%-104.7% with the RSDs of ≤ 3%. The RCFs of liquiritin apioside and liquiritin were calculated by methods validated as 0.49 and 0.38, respectively. The determination results reflected the good reproducibility of the RCFs in different influence factors. There was no significant difference between the calculated values by QAMS method and the measured values by ESM. The results of stability investigation showed that the contents of liquiritin apioside and hesperidin decreased rapidly under high temperature condition for long time, while liquiritin decreased gently, implied that the storage time of traditional Chinese medicine mixture should not be too long. CONCLUSION The method applied in this study is accurate, reliable, reproducible, and can be used for the quality control of Bazhen Yizhi mixture. This mixture should be sealed and stored in a cool place.