Various methods have been developed for retrofitting and improving flexural and shear performance of RC beams. Retrofitting of RC beams using external steel plates is one of common and proper methods that have been investigated in recent years. This research studies behavior of damaged RC beams that have been repaired and strengthed with external steel plates. Two RC beams that had been damaged significantly under quasi-static pushover loading in flexural region, are repaired by means of shear and flexural steel plates and again, are loaded under quasi-static pushover loading. The bonding mechanism of external steel plates with concrete beam is the difference between specimens. One of the specimens has adhesive bonding and the other one has adhesive bonding with mechanical anchors. The result show that the strength and stiffness of both specimens has increased through the repairs, but the strength and stiffness of the specimen with adhesive bonding with mechanical anchors is greater than the specimen with adhesive bonding. The repaired specimens have limited ductility with respect to the intact ones.