Drosophilidae is a large taxon which contains more than 3,000 species and ranges from boreal regions to tropics. The developed habitat segregation among drosophilid species which could ease the interspecific competition is considered to be one of the mechanisms for maintaining drosophilid species diversity. In forests, the habitat segregation among drosophilid species is especially noticeable in vertical direction, and canopy community is quite different from forest floor. I will present the degrees of the importance of this vertical segregation, beta diversity in vertical direction, to local dorosophilid species diversity in boreal, cool temperate and tropical forests using an additive partitioning model with individual-based randomization test.