Abstract: OBJECTIVE To study the feasibility of determination of three ingredients in Platycodonis Radix by quantitative analysis of multi-components by single marker(QAMS). METHODS With HPLC-ELSD as its detect method, chromatographic patterns of Platycodonis Radix extract in different chromatography instruments and columns were studied for positioning chromatography peaks of three ingredients. Then platycodin D was used as reference to create RCF with platycodin D3 and platycodin E, meanwhile, the content of platycodin D was determined by external standard method(ESM) and the contents of platycodin D₃ and platycodin E were calculated by RCF. The results measured by ESM and QAMS were compared to discuss the feasibility of determination of three ingredients in Platycodonis Radix by QAMS. RESULTS The method had good repetition and durability, 10 batches of Platycodonis Radix were analyzed and the results showed there was no significant differences between two methods. CONCLUSION QAMS can be used to determinate several platycodins in Platycodonis Radix.