The scope of doctoral dissertation is research of the seismic resistance of masonry buildings, reinforced with FRP (fiber reinforced polymer) and FRM (fiber reinforced mortar). Several systems for strengthening of old brick walls were tested in-situ and new stone walls in the laboratory. The efficiency of the bond of the brickwork and composite coverings at shear forces for all systems were further investigated in small clay samples in the laboratory. The results of in-plane shear tests have shown good performance of strengthening by horizontal reinforcing carbon strips and glass mesh in a modified cement mortar, however reinforcement with diagonal carbon strips was less effective. Investigations of shear contact on small brick samples with FRP/FRM cover led to the conclusion that for the efficient strengthening the good basis preparation and sound anchoring of the ends of the strips are necessary. The objective of the own experimental investigations and in-depth study of this scientific field was the evaluation of the existing calculation models and the integration of improved model in the software for computation of seismic resistance of masonry buildings. Nonlinear seismic analysis of the building performed based on newly developed computational model, shows that for the unreinforced building the earthquake resistance can be determined well, just as high as the TREMURI framework mechanism because the new calculation model has been improved. In addition, the new calculating model in SREMB can also be used to calculate buildings strengthened with FRP / FRM materials, horizontal, vertical, diagonal and all possible combinations.