Masonry is the construction technic that use stones or other similar material, united with the use of mortar, in order to form a wall. Masonry developed widely with the expansion of large urban civilizations and sign a passage to a period of long-lived, solid and complex structures. In a first period, building were realized block elements without the use of a mortar, that were united only by the friction between the elements surfaces. Romans developed many masonry technics, called opus, that were distinguished by cut and dimensions of the blocks. The great turning point of the masonry technic was signed by the discovery of the quicklime. The blocks were then positioned on beds made of mortar that drying formed a more solid structure. In Italy the greatest part of the constructions realized before the 60ies is built in masonry. Popular are farmhouses in masonry opus incertum. Having an architectonical point of view, masonry doesn’t permit a use of big openings or non-regular shapes, making masonry a an unsuitable system for modern buildings. These kind of building are characterized by a regular shape, studied openings, and load bearing walls continuous that reach the roof. The seismic safe of the building depends then on the regularity of the structure, that is the base element of this kind of structural system.