The transformation processes that occur in the technical, informational, and economic spheres of the regions require the development of new conceptual approaches to the development of a full-fledged land use system based on an analysis of the problems of using underground real estate. Determination of the features of land use of underground real estate is based on a quantitative basis, which is built on a systematic, integrated approach. Indicators that determine the condition and use of underground real estate are of particular importance for the development of the approach. A method of estimating a generalized indicator of the use of underground real estate in the system of land use of regions based on an integrated approach, which includes the method of expert assessments by applying qualitative indicators characterizing the status and level of use of underground real estate, considering urban, spatial, investment and innovation legal and safety features is developed. The assessment results of the integrated indicator of underground real estate land use, as well as the results of the assessment by region, showed a low level of use of underground real estate in the land use system of the regions. It is determined that most of the lands in the regions have low levels of underground real estate use. Besides, there is a need to increase the use of underground real estate by developing appropriate methodological recommendations.