The intensive use of steppes' resources has resulted in reduction of a biodiversity and a number epigeal animals. If the plot will be isolated from agricultural activity, it will gradually turn in to the present virgin soil. It is process of natural steppeformation.

The purpose of the research is the estimation of the process of microarthropods' complex formation (Acarina and Collembola) of ordinary chernozem of Nizhnii Don by means of natural steppeformation. The investigations were carried out in 70-, 15- and 5-years old fallow land and adjoining to them an agrocenosis in Mjasnikovskii district of the Rostov region.  The selection of soil samples was carried out in May, July and October. Soil samples were taking layer by layer through 5 cm up to 30 cm in depth 15 times. The extraction of microarthropods (Acarina, Collembola) from the substratum was conducted by way of eclectors at natural lighting without electric heating for 7 days up to full drying up with the following storage in 70 % alcohol with the addition of glycerin.

During the investigations it was established, that the minimal number of all researched groups of microarthropods is fixed in all terms. The increase in number microarthropods is registered with the increase of the age of fallow land. On all researched plots two peaks of number it is marked in May and October, in July its sharp reduction in all researched groups is observed, and in this very period the most populous a soil stratum is 10-20 cm. In total 39 species of collembola were revealed for the period of research: 21 in agrocenosis; 25 in 5-years old fallow land; 28 in 15-years old fallow land; 35 in 70-years old fallow land. Ceratophisella succinea and Mesaphorura sp.gr. krausbaueri were the center of dominating species on all researched plots. Species, inhabiting in topsoil, haven't been discovered in agrocenosis and in 5-years old fallow land. Entomobria handschini, inhabiting in topsoil, is registered on 15- and 70-years old fallow land. The change of vegetative communities on fallow land of ordinary chernozem depends on time steppeformation of landscapes. That resulted in increasing of number of all researched groups of microarthropods and structure of collembola species.