The rehabilitation and strengthening of reinforced concrete members using Near Surface Mounted (NSM) technique has proven its success and becoming popular in the world of construction. The NSM technique using carbon, aramid, and glass fiber reinforced polymers (FRP) bars has attracted the attention of many researchers during the last decades. This paper presents a numerical analysis investigation of the behavior of strengthened beams with Three types of FRP; carbon fiber bar (CFRP), aramid fiber bar (AFRP), and glass fiber bar (GFRP) in flexural. Three dimensional finite element beam models are created on the finite element software ANSYS-2013 to study the flexural response of the investigated models. The constructed non-linear finite element models were verified by the experimental work results that are available in reference. A parametric study was conducted to examine the effect of type, number, diameter of NSM FRP bars, and bond length on the flexural response and ultimate load carrying capacity of the strengthened beams. Some of the studied parameters affected the strength capacity, stiffness, ductility and energy absorption of the beam models.