Abstract: High performance liquid chromatography （HPLC） was utilized to analyze the variations of Platycodin D content in stems and leaves in Platycodon grandiflorum （Jacq.） A. DC., which were collected from May to October from Shangluo area, and the study was aimed to explore the variations of main secondary metabolites in stems and leaves. The results showed that the contents of Platycodin D were stably in the stems from May to October, and the peak was reached in September; the contents of Platycodin D were highly in July and August, yet the content decreased dramatically in October. Furthormore, the average content of Platycodin D in leaves （0.614%） was higher than in stems （0.257%）. Therefore, the young stems and leaves also could be used as medicines, and their harvest time should be August in Shangluo. By investigating the variations of Platycodin D content in stems and leaves in different months, the study can provide references for medicinal parts and harvest time and standardization production in P. grandiflorum in Shangluo.

Key words: Platycodon grandiflorum, HPLC, platycodin D, different months, stems and leaves