In connection with large-scale contamination of soil by oil and oil products are extremely relevant studies of the properties of quantitative and qualitative changes in the rocks. It is known that the transformation of oil starts practically from the first minutes of its income to the ground surface. Its movement as well as transformation processes proceeds with varying intensity, depending on many factors. These are properties of the environment-"recipient" (physical, chemical, the presence of biota), and the characteristics of the oil (oil products). However, the consequence of transformation is not a primitive decomposition of oil, the formation of new compounds, which are in some cases more toxic. In this connection it is necessary to evaluate the properties of contaminated soils, particularly the prospects for preservation of constructions, located in the zone of contamination. The polluted geological environment becomes a characteristic of its type of geochemical zonation which is not peculiar to the normal natural conditions. The article focuses on the activity of living matter in the oil contaminated soil, which is a prerequisite for the evaluation of complex geo-environmental risks associated with the transformation and migration of hydrocarbons.