Lateral behavior of RC Buildings is a great importance when it is in question the earthquake happening, so in this paper are presented the differences between buildings which have slabs without beams compared with those that in their slabs have included beams. Analysis is done for low and middle rise building, because these buildings are predominant in our region. The reason why we have analyzed here the lateral behavior of such cases is due to the fact that nowadays around us are used so many building using slabs without beams because they represent a flexible solution in functional organizing the internal area in the aspect of architectural requirements. Analysis is done for some typical cases just to present the differences in the aspect of lateral behavior and important parameters such are: inter-story drifts, top displacements and some other similar parameters when is in question the lateral displacements
