Despite its ecological importance, little information is available regarding spatial and seasonal changes in the testate amoebae community in peat bogs. The objectives of this study were to examine the structure of communities and horizontal distribution of testate amoebae fauna, to improve the understanding of factors affecting the distribution of moss testate amoebae communities and to analyze the seasonal changes in testate amoebae communities in a Sphagnum-dominated peat bog (eastern Poland). A total of 45 testate amoebae species were identified in the samples. The highest species richness occurred in hollows dominated by