Ectomycorrhizal (ECM) fungi are mutualistic root symbionts that play crucial roles in ecological processes such as element cycling, nutrient mobilization and plant community dynamic. Their key roles in ecosystem functioning is of primary interest for ecological restoration of human disturbed land areas. New Caledonia, an archipelago located in the South West Pacific, is well-recognized for its exceptional biodiversity. Mining activities combined with fires and past logging have lead to the drastic reduction and fragmentation of its original rainforest on ultramafic soils. In order to develop future restoration programs in New Caledonia, we aim to characterize the ECM fungal communities within different rainforest formations representing different states of forest dynamics, i.e. mixed rainforests and rainforests dominated by Nothofagus aequilateralis (Nothofagaceae) or Arillastrum gummiferum (Myrtaceae). ECM communities have been assessed by sequencing the Internal Transcribed Spacer (ITS) from mycorrhizae collected in the soil. Our preliminary results suggest a strong belowground diversity and the dominance of the /cortinarius lineage under N. aequilateralis. Based on their abundance, species belonging to this lineage could thus represent suitable strains for further plant inoculation purposes. Furthermore, this work will increase our knowledge about ECM fungal biodiversity in tropics, regions that have been poorly studied to date. This study will also be placed in the broader context of the on-going plant-microorganisms interactions program undertaken within the "Institut Agronomique néo-Calédonien".