Propensity increase to use high buildings due to lack of urban spaces and the need to restriction the horizontal expansion of cities, encouraged engineers to use varied designs to Eye-catching appearance in buildings with geometric and structural form changes. Spiral shapes are one of the expanding models of the third millennium that similar samples can be seen in developed countries. This study considers behavior function analysis of long spiral structures, compared with similar conventional structures. In line with this research, we analyzed a building with fifteen-story reinforced concrete system in two cases, spiral structure with central core (rotation in floors) and conventional structures (without rotation in floors). This study case dynamically analyzed in similar mechanical features and specifications with ETABS software and the results were recorded and compared. The results of similar behaviors in two models shows that the central core has a major impact on the structural behavior of the spiral model.