In Egypt, many existing buildings are vulnerable to seismic action. Most of these buildings have ordinary non ductile RC elements, beams and columns infilled with brick walls (infilled RC frames). A number of experimental studies have been reported in recent literature about the beneficial effects of infill walls on the seismic response of RC frames. In this study, behavior of infilled RC frame was investigated with three different micro models using Abaqusstandard package. The analysis included 2D model using plane stress element, 3D model using shell element, and 3D model using solid element. Results indicated that the three models, (2D model using plane stress element, 3D model using shell element, and 3D model using solid element) were able to predict the actual behavior of the bare and infilled RC frames efficiently. Given the minor difference of the behavior observed between the three models and with reference to CPU time, it can stated that, the 2D Plane stress element is the most effective model among the three models. Of course this statement depends on the target of the modelling process.