The aim of this study was to elucidate composition and diversity of soil fungi of seasonal tropical forests in Northeast Thailand (Sakaerat Environmental Research Station), to explore effects of forest types (3 dry deciduous forest [DDF] plots vs. 3 dry evergreen forest [DEF] plots) based on a pyrosequencing analysis. In 818 fungal operational taxonomic units, 94% were identified to phylum, which was same level with that from temperate forest soils. At phylum level, 71.4% belonged to Ascomycota and 21.5% was Basidiomycota, while 90 were putatively ectomycorrhizal fungi and 16 of arbuscular mycorrhizal fungi. Soil fungal species composition was significantly different between 3 forest types and between DDF plots despite no difference between 3 DEF plots. Tree species composition could not sufficiently explain underground fungal species composition. Undergrowth dwarf bamboo might contribute to form the difference of soil fungal species composition in DDF plots. This study disclosed fungal community structure in main seasonal tropical forest types in Thailand.