Abstract: OBJECTIVE To study the dynamic changes of three active components of chongqing miaoyu Codonopsis pilosula with different growth years, and to provide references for the standardized planting, harvesting and quality control. METHODS UV method was used to determine the content of polysaccharides and total saponins, and HPLC was used to determine the content of lobetyolin. RESULTS In 1-4 years, the content of polysaccharide increased with the increase of growth years. Compared with first year, the content of polysaccharide in fourth year increased about 100%. However, compared with the fourth year, the content decreased about 10% in fifth year. In 1-5 years, the total saponins and the glycosides of codonopsis pilosula increased year by year, compared with first year, total saponins increased by about 57% and lobetyolin increased by about 42% in fifth year. The content growth of polysaccharides, total saponins and lobetyolin were not significantly correlated. CONCLUSION According to the growth trend of active ingredients, production cost, production efficiency and yield of medicinal herbs, Chongqing Miaoyu Codonopsis pilosula should be harvested after 4 years' growth.