This article deals with the effect of rock textures on the slope stability in open cast mines and roads on mountains. Physical models were molded from Portland cement, quartz sand, basalt particles of different sizes in order to produce artificial rocks differ in their textures. Three kinds of rock textures where yielded; they are coarse, medium and fine textures. The bench height, berm and the angle of slope were also varied   to study the effect of rock textures on the slope stability of open cast benches having coarse texture, grains larger than 5mm. It was found that the benches will only be stable when the height of bench is equal or less than 1.4times their berms and the slope angles should be less than 75 degree. Failures will occur at slope angle near 90 degree as result of both tension and shear stresses. No failure would occur for rocks having fine texture, with medium texture rocks, the failure depends on the bench height.