Earthquake is the most expensive natural disasters human face. Strong earthquake in the wrong place at the wrong time can cause great financial damage and cost. And in the present stage, many buildings are irregular in shape means both plan and elevation irregularities earthquake effect on high rise building is more dangerous as compared to a regular building. To overcome the effect on the earthquake on a regular building, it is necessary to identify the performance of the structure to withstand against disaster against both new and existing one. In this paper, the behavioral study of 5 bays X 5 bays 8m each of G+7 building with a provision of lift core walls are done. The height of each storey is 3.2m and have irregular plan and elevation. In this study, cases like a bare frame, boundary infill, complete infill and soft storey at ground floor for each model are considered. All buildings are located in zone III. Linear dynamic analysis using response spectrum method of irregular building is carried out using ETABS 2016 Ultimate 16.2.0 by considering mainly three irregularities (1) Mass irregularity 2) Stiffness irregularity (3) Geometric irregularity. For this study, behavior parameter considered are (1) Eccentricity (2) Maximum storey displacement (3) Time period (4) Maximum storey acceleration (5) Storey shear.