The historical masonry buildings form widespread spectrum of existing buildings in IRAN. destruction on structures illustrate that historical masonry buildings have maximum damages due earthquake, in addition they don't actuate properly about seismic behavior (the main reason of this is lack of proper ductility). Shear of the masonry walls, is the only structural element of these type buildings, undertake gravity load and lateral load. This is the main reason that leads to researchers think over techniques about improvement and strengthening the walls, and also leads to experiencing real samples and scaled models. In this essay, at the beginning was introduced a method about modeling finite elements unreinforced masonry (URM) wall by using of software (ANSYS). In order to verifying the correctness of modeling, it's require to do experimental test on a sample of wall and then that wall should be modeled by illustrated method. Then correctness of modeling method and analyzing method should be verified by comparing the result of numerical modeling with the result of modeling experimental. The experimental model has been examined at Shiraz University. The result of numerical modeling and analyzing illustrate that lateral load-displacement curve is stiffer than experimental curve. And lateral load carrying capacity has precision about 99.28 percent, and lateral displacement has precision about 94.1 percent. also the numerical results agree reasonably well with the experimental results. In the next stage the masonry walls are strengthened with Carbon Fiber Reinforced Polymer sheets (CFRPs). five different strengthening methods have been used with different thickness. The strengthened walls are affected by vertical loads and in-plane shear. It is found that the critical loads, the critical displacement, the ultimate loads, the ultimate displacements and the ductile coefficients of the masonry walls strengthened with CFRPs improve remarkably. © (2010) Trans Tech Publications, Switzerland.