The mechanical properties of the brick in combination with mortar play important role in masonry buildings. The appropriate composition and behavior of the masonry walls reduce most of the damages when masonry buildings are subjected to lateral loads such as earthquake and consequently structural performance is enhanced. Knowing mechanical properties of mortar, masonry units and masonry walls are crucial for selecting proper material and construction practice. In addition to properties of bricks, grading, water-cement ratio and cement content affects strength of mortar and accordingly strength of masonry walls. In this experimental study, mechanical properties of cement mortars with 1:3, 1:4 and 1:5 (volume ratio of cement: sand) is studied; then compressive strength, flexural strength and water absorption of hollow bricks were investigated. Finally, mechanical properties of masonry prism with hollow bricks including compressive strength and shear (diagonal tension) strength are determined based on standard test procedures. results shows that when compressive strength of mortar increases, the ratio of compressive strength of masonry prism to compressive strength of brick increases too.