Seismic pounding between adjacent buildings has been frequently observed during past earthquakes. This phenomenon can significantly increase seismic demands, often leading to severe global or local damage and even partial or total collapse. This study investigates the seismic response and both inter-story and story-story pounding behavior of adjacent RC buildings with different dynamic characteristics by ETABS software using nonlinear time-history analyses. Eleven recorded earthquake ground motions are employed to capture comprehensive excitation characteristics. The numerical model includes nonlinear flexural and shear plastic hinges and contact elements to simulate impact interaction between the structures. Global response parameters including inter-story drift ratios, displacement demands, and acceleration demands, and local response parameters including impact force, column shear force demands and plastic hinges behavior are obtained and analyzed to identify the critical stories and gap separation levels associated with pounding occurrence. The results indicate that increasing the gap distance does not necessarily guarantee a reduction in localized damage resulting from story-column pounding. This is due to non-monotonic relationship between separation gaps and impact velocity while intermediate gaps producing high relative velocities at impact which induced and may lead to greater contact forces and a more rapid degradation in stiffness.