This book aims to understand and learn the concept and procedure involved in the design of Base Isolated Structures. The base isolators are designed in accordance with the UBC-97 code provisions for the isolated structures, and the super structure is designed in accordance with ACI-99 code. The analysis and design is carried out with the help of a structural analysis software named ETABS (Extended Three Dimensional Analysis of Building Systems). The type of analysis performed is static linear and P-Delta effects are also incorporated in the analysis with the help of the analysis software. First a fixed base structure is modeled and analyzed. The base shears calculated from the analysis of the fixed base structure is then used to calculate the stiffness of the isolators and to set the design displacement and time period of the base isolated structure. After the design of structures, both fixed base and isolated base, a comparison between the two is made to study the effects of implementing the base isolation technique.