Gamasida (Acari, Parasitiformes) is one the most diverse group in mites, and they inhabit in various environments, for example soil, tree canopy, tree trunk, leaves, animal, inter-tidal zone. About 10,000 species have been described in the world, half of them are predatory mites in soil and litter, and they prey on nematodes, small insects and mites. Although many predatory gamasid mites have been recorded from soil and litter in Japan, difference of diversity and difference of species composition of gamasid mites in different soil environments have not surveyed and discussed yet. In the present study, we surveyed soil gamasid mites in urban environment in Sapporo City, Hokkaido, Japan, and compared with gamasid mites in secondary forests (mixed forest, deciduous broad-leaved forest) in and near Sapporo. Our study focused on the following points: 1) difference of diversity in each environment; 2) characteristic taxa in each envrironment; and 3) availability of some taxa as bioindicator to evaluate environment. Number of species and index of diversity were higher in the fauna of secondary forests. Diversity of the families Parasitidae and Laelapidae were higher in urban environment fauna, while diversity of Parholaspidae and Veigaiidae were higher in the forest one. In the forest, mites of the family Zerconidae appeared exclusively, whereas one species of the family Parholaspidae and Parasitidae were dominant in urban mite fauna. Family Zerconidae and some species of Parholaspidae and Parasitidae may be available as bioindicator to evaluate soil environment.