Abstract: In order to explore the optimal Phyllostachys praecox density in Phyllostachys praecox-Polygonatum sibiricum intercropping models, three kinds of bamboo density: low density D₁ (6000~9000 stems·hm⁻²), medium density D₂ (9000~12000 stems·hm⁻²) and high density D₃ (12000~15000 stems·hm⁻²) were set in the extensive management of Phyllostachys praecox forest as the test area, and the effects of these three different bamboo density on the growth and development, biomass accumulation and the medicinal value of Polygonatum sibiricum were analyzed. The results showed that the three bamboo densities had different effets on the plant height, ground diameter, biomass, chlorophyll content and leaf relative characteristics of Polygonatum sibiricum. Under D₁ density, the aboveground and belowground biomass of Polygonatum sibiricum was the largest, the dry matter content of leaves was the highest, and the dryness rate of aboveground and underground parts was the largest. Meanwhile, there was no significant difference in the total polysaccharide content of Polygonatum sibiricum and the total saponin content of Polygonatum sibiricum under the three bamboo densities. This study clarifies that the bamboo density is an important factor affecting the growth of Polygonatum sibiricum under the Phyllostachys praecox forest, and the suitable bamboo density for the combined management of Phyllostachys praecox-Polygonatum sibiricum is 6000~9000 stems·hm⁻².