Objective: To isolate and identify pathogen of the seedling blight occurred in Platycodon grandiflorum.
Method: The morphological observation, rDNA ITS sequence analysis, and Koch's postulates were used to identify the isolates of the causal agent.
Result: The isolates of the causal agent was Rhizoctonia solani.
Conclusion: The result confirmed that R. solani is the pathogen of seedling blight of P. grandiflorum.