Platycodon grandiflorum is a perennial economic crop. It can be used as medicine and food. As a perennial plant, planting-years can also affect the interaction between the root and the cultivation environment. In order to determine the best planting years of Platycodon grandiflorum, 15 agronomic traits of two different planting years of Platycodon grandiflorum were tested, such as root weight, stem diameter and plant height. The biomass distribution of the two planting years Platycodon grandiflorum were tested too, including roots, stems, leaves, flowers, buds and fruit. Environmental factors such as the light strength, dew point temperature, humidity and surface and subsurface temperature were tested during the flowering time. The results showed that most agronomic characters of biennial Platycodon grandiflorum were better than those of three years old, including the plant height, root length, leaf area, primary branch number, secondary branch number, flower, buds and fruit number. At the same time, the field environments such as surface low temperature, high humidity, strong light of biennial Platycodon grandiflorum during flowering time were better than those of three years planting Platycodon grandiflorum. All these environments of biennial Platycodon grandiflorum were related with its excellent comprehensive agronomic performance. According to the investigations of Platycodon grandiflorum in Anhui area, planting period of two years is preferred.