Abstract In order to study the species richness of oribatid mites in rangelands of West Azerbaijan Province (Northwestern Iran), soil samples were taken in eight different sites of rangelands including Ghooshchi (1600–1750 and 1750–2000 m a.s.l), Ghasemloo (1300–1450, 1450–1600 and 1600–1750 m a.s.l) Roze-Chai (1450–1600 m a.s.l), Marmisho (1750–2000 m a.s.l) and Ordooshahi (1300–1450 m a.s.l) areas at three different times (mid-May, mid-August and mid-October) of the year 2012. In total, 71 species belonging to 49 genera, 32 families and 20 superfamilies were collected and identified. The oribatid species richness was calculated for all the samples with the Ecological Methodology 6.0 software. One-way ANOVA revealed significant differences (P< 0.01) in oribatid species richness among sites (P< 0.01). Ghasemloo 2 (44 species) had the highest species and Ordooshahi (14 species), Ghooshchi 1 (19 species) and Roze-Chai (24 species) had the lowest species richness, respectively. Also, there were significant differences (P< 0.01) in species richness at different altitudes. In this regard, Ghooshchi 2 and Marmisho (1750−2000 m a.s.l) had the highest species richness among the studied areas.
