Soil-structure interaction is often a difficult problem to study. This article uses Wolf’s Cone Model and its application in the substructure method to investigate the effect of soil-structure interaction on natural period of conventional buildings. In accordance with Iran’s Construction Code 2800, five soil types were considered. The studied structures were 4, 7, and 10 storey buildings. The following results were obtained: 1) The interaction between soil and structure was much more pronounced in finer soils, 2) The relative change in period was greater in shorter buildings, 3) The soil-structure interaction decreased as the ratio of “foundation dimension to soil thickness layer” increased.