This study aims at considering the effect of columns size on the seismic performance of reinforced concrete structures, in this article, three RC frames with different columns sizes have been analyzed. The five-storey building is analyzed for seismic force by Choosing three different type column cross-sections of the structural mechanism. i.e. (60x45) cm, (550x45) cm and (50x40). To assess the behavior of multi-storey building under seismic action Nonlinear static analyses for lateral loads were performed by using standard package SAP2000 software. The comparison of these frames for various earthquake response parameters like stiffness and base shear with roof displacement was executed. It is observed that the seismic efficiency in frame 1 of column dimensions(60x45) cm was significantly large with small displacements and The results are well-illustrated in this article.