This paper studies the behavior of simply supported steel I-beams strengthened with carbon fiber reinforced polymers (CFRP) strips on the web as shear reinforcement. The experimental program contains seven simply supported steel beams. One of them was considered as a control beam and the other specimens were strengthened with different schemes; varying the position of CFRP strips to the web, its number of layers and its angle of orientation. The results show that applying CFRP strips on the web of the steel I-beams was an effective strengthening method for increasing the load bearing capacity and decreasing the deformations. Using two layers of diagonal CFRP strips on both sides of the web realized the highest increasing in the load capacity. Moreover, finite element analysis method has been utilized to analyze the tested specimens using ANSYS. A great convergence between the experimental results and the corresponding ones obtained from finite element simulation