We took 60 samples in the post-mining chronosequence with different stages of ecological succession (4 sites) in 2005 and 2006. In total, 2,740 specimens of soil microarthropods were extracted and classified according to the Biological Quality of Soil Index (QBS-ar). The number of taxa of microarthropods and QBSar values increased with succession. According to the increasing values of QBS-ar, the soils of the study sites can be ordered along the following sequence: the youngest part of the dump (the two-year-old site) (S I) – the four-year-old site (S II) – the ten-year-old site (S III) – the twenty-year-old site (S IV) (mean QBS-ar = 40; 94; 120; 140, respectively). The QBS-ar index indicated better soil biological quality in woodland sites. The correlation between QBS-ar values and time of chronosequence was presented.