The Cypripedium japonicum is a species of orchid, distributed mainly in the temperate regions of the Northern Hemisphere. In Korea, C. japonicum is an extremely rare species and class I endangered plant. However, little is known about the plant-microbe interaction and its ecology, especially rhizosphere bacterial communities in terms of structure and diversity in C. japonicum. In this study, the diversity of bacterial communities was investigated in C. japonicum rhizosphere and bulk soil. Proteobacteria, Acidobacteria and Actinobacteria were the most abundant groups in both rhizosphere and bulk soil. Significantly Proteobacteria and Actinobacteria abundantly inhabited in the rhizosphere when compared with the bulk soil. Conversely, significantly more unclassified bacteria were detected in the rhizosphere soil than in the bulk soil. This work increases our understanding of the rhizosphere bacterial diversity on class I endangered plant, C. japonicum.

Introduction
 Materials and Methods
  1 Field collection of rhizosphere and bulk soil of C.japonicum
  2 Soil DNA extraction, amplicon preparation andpyrosequencing analysis
 Results and Discussion
 Acknowledgment
 References

• Hye Sun Kim(Division of Applied Life Science(BK21 Plus) and Institute of Agriculture and life Science, Gyeongsang National University)
• Geun-Hye Gang(Species Restoration Technology Institute, Korea National Park Service)
• Eun-Hee Park(Species Restoration Technology Institute, Korea National Park Service)
• Youn-Sig Kwak(Division of Applied Life Science(BK21 Plus) and Institute of Agriculture and life Science, Gyeongsang National University) Corresponding author