The study results of the post-fire changes in soil mesofauna of the pine forests in south-eastern outskirts of Minusinsk depression. The main directions of regenerative processes are revealed in the structure and number of mesopopulation of soils within burnet areas of different age. In the first year after fire numerical indicators of soil invertebrates are reduced up to a critical level, however steppe species penetrate into the population structure. Further, the main environmental parameters of the forest ecosystem change and habitat conditions become more favorable. Almost all groups of invertebrates are gradually building back as a part of mezopopulation, natural biodiversity of soil communities increases at the taxonomic level.