These book deals with the comparative study of performance of multistory R.C.C. building for floor wise reduction of column cross section and constant column cross section. For this study a G+6 storey R.C.C. building in Zone IV is selected. Horizontal seismic forces are calculated based on Equivalent static method. The R.C.C component like beam and column are designed by preparing Microsoft Excel sheet based on analysis result. The columns are designed as constant column cross section and reducing column cross section. The push over analysis is carried out on the building frame model with constant column cross section and floor wise reducing column cross section separately using SAP 2000 Software package. A comparative study is carried out for the formation of plastic hinges on column and beam, base force and displacement of the building model for constant column cross section and reducing column cross section. A comparative study of Bending moment and Shear force for the building model is also carried out constant column cross section and reducing column cross section.