In this paper, steel ordinary moment resisting frame buildings designed according to the Iranian Earthquake Code (Standard No.2800, 2nd edition) are evaluated based on seismic retrofitting provision for existing buildings. Also, their seismic performance is investigated in the range of both linear and non-linear behaviors. At first, several common samples of these systems were designed through 2800 code. So, critical frame of these samples was controlled using the seismic retrofitting provision in base upgrading level through the several detailed numerical analyses (non-linear static, linear dynamic spectrum and time history). Based on the obtained results, bending performance of all members in all structures is controlled by deformation and with linear dynamic time history analysis using the record of happened earthquakes in Iran such as Bam, do not need to be strengthened. The shearing low-height structures showed a reasonable performance in the range of non-linear behavior. However the flexural structures (6 and 8-storeyed) with non-linear static procedure and all of structures with linear dynamic spectrum method should be improved.