A study of mattress-dust mites from 19 localities from East Algeria and various climatic zones shows the presence of many ubiquist species. Four species of Pyroglyphidae have been extracted: D. pteronyssinus Trouessart, D. farinae Hughes, D. siboney Dusbabek et al., and E. maynei Cooreman. Different species of Glycyphagidae, Acaridae and Cheyletidae (except C. eruditus) are often found in a considerable number. The count and study of species composition show the abundance of D. pteronyssinus with 85,57 % of total fauna, E. maynei with 3,55 % and D. farinae with 2,71 %. T Test indicates a significant difference in the density of population between humid and dry zone on one hand and between high and low altitudes on the other hand. Acari population distribution depends of different factors. In principal component analysis, three factors appear: climate, altitude and food.