Abstract: In order to further improve the yield and root quality of edible Platycodon grandiflorum,soil improvement was carried out with substrate before sowing（adding different proportions of coconut bran and peat）,and combined treatment was carried out with different densities.The best cultivation conditions of edible Platycodon grandiflorum were determined by exploring the effects of different cultivation densities and substrate treatments on various characters of edible Platycodon grandiflorum.The results showed that stem diameter, branch number, shoot fresh weight, root diameter and single root fresh weight were significantly affected by density, and increased with the decrease of density, but there was no significant difference among the three treatments; The root length of B₃（20% coconut bran + 20% peat + 60% native soil） was significantly higher than that of the other two treatments; The results of membership function analysis showed that the best cultivation combination of edible Platycodon grandiflorum was A₂B₃（cultivation density 4 cm×4 cm）,substrate treatment（20% coconut bran + 20% peat+60% original soil）.