Abstract: Studies on ecological distribution of filamentous fungi in forest soils of Guangxi indicate: 1. the quantity of filamentous fungi is closely related with forest type,soil moisture and soil organic matter content,which is greater under coniferous than under broadleaved forest,and greater in soils with higher moisture and organic matter contents;2.Peniclilum,Trichoderma, Aspergillus,Humicola and Phoma are dominant and the first two genera have the greatest relative density.