This study was conducted to investigate the diversity of ectomycorrhizal mushroom by surveying sites from June 2004 to October 2005. The obtained results from investigation were as follows. The total of 5 classes 16 orders 63 families 149 genera and 358 species including saprophytic and ectomycorrhizal fungi was investigated. A total of 17 families 36 genera 152 species (1,285ea.) of ectomycorrhizal mushroom was investigated. The mushrooms are classified into 9 families 27 genera and 136 species in Agaricales, 5 families 6 genera and 12 species in Aphyllophorales and 3 families 3 genera and 4 species in Gasteromycetes. Dorminant species were Russulaceae (35 species) followed by Boletaceae (34 species), Amanitaceae(22 species) and Cortinariaceae (21 species). The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature and lots of rainfall from July to September. The environment factors which have a favorable influence of mushroom occurrence were soil pH, available P₂O₅ of soil and rainfall and air temperature of climatic environment.