In the framework of this project, an attempt was made to find out the influence of the shape, size and direction of the . rectangular columns of the construction plan on the general stiffness and seismic response of the building suffering from the earthquake. A multistory RC building is modeled using ETABS software with different column shapes (square and rectangular), column sizes (different cross-sectional area at building height), and column orientations to determine the effect of each on the stiffness and seismic response of the building.