Wrapping of concrete column by means of Fiber Reinforced Polymer (FRP) reinforcement can significantly improves its structural behavior. The efficiency of wrapped FRP strengthening technique depends mainly upon the encountered parameters related to the original conditions of the element to be strengthened as well as upon both the volume and configuration of the wrapped reinforcement. The rectangularity of the cross-section can play an important role on the efficiency of the applied strengthening technique. This research aimed to analytically investigate the contribution of bonded wrapped Carbon Fiber Reinforced Polymer (CFRP) sheets to the axial compressive strength of concrete columns. Based on the experimental results, obtained by the author and Yu-Fei 2010, concerning the load carrying capacity of rectangular concrete columns confined with CFRP sheets, a study to address the applicability of the proposed analytical models (Egyptian code EC, American Concrete Institute 'ACI' code) to predict the compressive strength of rectangular columns confined with CFRP sheets is presented in this research. The proposed models showed an underestimation in predicting the compressive strength. This is attributed to, from the author point of view, that both of the proposed models haven't taken into account both the contribution of internal stirrups and the real effective strain induced in the confined FRP sheets. To treat such a problem and on the basis of the results of the experiments of 22 specimens, the author suggests a modification in both proposed codes "Modified Egyptian code" and Modified ACI code". Such a modification takes into account the effect of the internal stirrups and the real effective strain of wrapped sheets when computing the compressive strength of FRP confined concrete specimens. As a consequence, the compressive strength of FRP confined concrete columns predicted according to the modified models showed an acceptable approach to the experimental results.