Paphiopedilum armeniacum S. C. Chen et F. Y. Liu is an endangered lady’s slipper orchid species with high horticultural value. As observed for other orchids, mycorrhizal fungiendophytic bacteria play important roles in the growthdevelopment of P. armeniacum. In the present study, the community structure dynamics across three growthdevelopment stages of cultivated P. armeniacum were investigated. The potential interactions between Tulasnellaceae fungicore bacterial genera on one handthe stability of the presumed mycorrhizal fungi communities on the other were analyzed in three growth stages of P. armeniacum to enhance our understanding of endophytic microbial community structure dynamics in the roots at different development stages. Based on sequencing, 316 phyla59269 genera were identified in the fungalbacterial communities, respectively. The predominant fungibacteria were Basidiomycota (62.90%)Proteobacteria (43.98%), which exhibited changes in abundancediversity depending on the growth stage of P. armeniacum. Assessment of the entire microbial communities from different growth stages showed that the seedling stage had the highest richnessdiversity. The microbial communities recruited by P. armeniacum at the seedling stage were different from those recruited at the vegetativereproductive growth stages,the microbial communities recruited in the latter two stages overlapped. Tulasnellaceae were the only dominant fungal symbionts during P. armeniacum growth. Brevibacillus, Mycobacterium,Sphingomonas, the three core genera, showed significant interactions with the main OTUs of Tulasnellaceae. Putative mycorrhizal fungi in P. armeniacum were relatively stable across different growth environments,the core mycorrhizal fungi were uncultured Tulasnellaceae (OTU1). This could facilitate the ex situ conservationcommercial development of the endangered orchid.