The publication deals with the problem of correction of an object that occurred during the social experiment carried out by one of the first Russian sociologists, a follower of Auguste Comte, Dmitry Arkadievich Stolypin (1818 – 1893). In accordance with the level of development of sociological science of the last quarter of the XIX century the definition of the concept of «social experiment» was formulated. The reasons for the social experiment, conducted by D.A. Stolypin during 1874 – 1893 in Mordvinovka Village of Berdyansk District of Taurida Governorate (present Mordvinovka Village in Melitopol District of Zaporozhye Region) were identified. Among them, as the main ones, are indicated the crisis of landlord economy and peasant land shortage, in the conditions of the development of agrarian capitalism in the south of Ukraine. It is proved that the goal of the social experiment completely coincided with the direction of the search for social support in the village by the imperial top. The analysis of historical sources allowed the authors to establish that its essence was to create rental farms on landowner lands increasing the profitability of the latter and to popularize among the local peasantry the leading forms of intensive local economic management. Research revealed that in accordance with the sociological concept of D.A. Stolypin local peasants were the object of the experiment, who were asked to break economic ties with the rural community and get the farm in the medium-term lease. The formulation of criteria for comparative analysis made it possible to distinguish three stages in the course of the experiment – 1874-1877 years, 1878-1888 years, 1889-1893 years. The main argument in favor of such approach was not the fact of introducing changes in lease agreements with farmers as much as the involvement of peasants from different social strata in the experiment. Authors found that at the first stage farmers were the representatives of the kulak and prosperous strata of the peasantry, at the second – among the wealthy tenants there were peasants of medium welfare, and at the third – the wealthy and middle peasants were equally divided. The intermediate results of the social experiments by D.A. Stolypin, which were researched in terms of improvements of material facilities, increasing the area of cultivated land and monetary incomes, including farmers in the channels of upward vertical social mobility and changing their social status. At the same time, the article emphasizes that scientific heritage of O. Comte, A. Smith, G. Spencer, as well as the foreign experience of agrarian transformations and knowledge of local economic traditions which were used by sociologist-amateur betrayed the ideas of the formed farm settlement. Social experiment D.A. Stolypin is described in the publication as the longest in the history of national sociology.