Earthquakes are one the world's deadliest natural hazards. Large earthquakes often strike without warning in areas of high population density, which can lead to catastrophic events. The National Earthquake Information Centre (NEIC) records an average of 20,000 earthquakes every year (about 50 a day) around the world. There are, however, millions of earthquakes estimated to occur every year that are too weak to be recorded. Most of the structures being RC frames which will have larger impact due to seismic loading. There are fundamentally two ways to improve the seismic performance of these structures. One method is to improve the deformation capacity of the beams and columns of these structures which is not always possible in practical situations. Another method is to add dampers or base isolators to increase the seismic performance of the structures. Adding dampers to the structures, in order to reduce the seismic responses, not only found to be effective but also economical in some of the constructions. Therefore, in this paper the efficiency of viscous damper on 3D-RC frame is evaluated based on placement of the dampers at different locations. FE analysis is carried out to study the dynamic behaviour of the structure.