Abstarct: Nowadays, rehabilation and retrofitting of existing structures is one of the effective ways to improve the performance of structures. Materials such as Fiber Reinforced Polymer (FRP) composites are a good choice in this regard. However, FRP loses its mechanical properties against fire due to the presence of polymeric materials and the reinforcing effect of FRP cannot be maintained. To address this problem, cement-baxsed materials were introduced by some researchers for reinforcing concrete structures with FRP, while most cement-baxsed adhesives lack proper ductility. Therefore, applied loads cannot be transferred from concrete to FRP composites and their fracture is generally brittle and shows no warning. It is necessary to produce and develop a cement-baxse adhesive with optimal ductility to be able to effectively transfer loads from the structural concrete to the FRP composites without being damaged at high temperatures. Engineered Cementitious Composite (ECC) is a promising and suitable candidate for such retrofitting and reinforcement applications. ECC ductility is obtained by fine cracks of less than 100 microns (in the strain hardening stage). In the present study, a numerical modeling of reinforced concrete beams retrofitted by engineered cement baxse materials and Basalt Fiber Reinforced Polymer (BFRP) grid was investigated. ECC was evaluated at different thicknesses as well as several fiber grids with different mechanical properties and diameters for reinforcement of the beams, and a numerical model was developed using ABAQUS software to simulate the beam under four-point loading test. Experimental results were used for validation and finally a parametric study on factors influencing beam resistance was performed. The results showed that increasing the thickness of ECC laxyer increases the flexural capacity of the strengthened beams. In addition increase in the diameter of fiber grids increases the flexural capacity of the beams only if debonding or crushing of concrete in compression does not happen.