This document compares the behavior of reinforced concrete (RCC) and steel-concrete composite multi-storey buildings through modeling and analysis. Three 10-story building models are created - one with RCC structure and two with composite structures using encased columns and concrete filled tubes. The models are analyzed using ETABS software to compare parameters like joint displacement, story drift, story shear, and cost. The results show that composite structures have higher joint displacements but lower story drifts and shears compared to RCC. Construction costs are also around 65% lower for the composite structures compared to RCC due to reduced concrete and rebar usage. In conclusion, composite structures provide better seismic performance and are more economical than conventional RCC