Indonesia is in an earthquake-prone zone; therefore, building structures must be designed to be earthquake-resistant. This research aims to evaluate the effectiveness of base isolation systems in enhancing the seismic performance of buildings. Specifically, the study compares the structural performance of buildings equipped with base isolation systems to those without, utilizing earthquake analysis spectrum response methods. The case study focuses on a 22-story apartment building, analyzed using ETABS V.18 software. The results indicate a significant increase in the period of buildings with base isolation systems. Although such structures exhibit notable lateral displacement, the inter-story drift remains relatively small. Furthermore, the base moment in buildings with base isolation systems is generally lower compared to those without, suggesting that base isolation can effectively reduce the seismic forces experienced by the structure.