Abstarct: appropriate corrective parameters for soil degradation and the need to research the type of clay is determined. In this study the effect of adding different percentages of nano clay and limestone to clay and clay soil shear strength parameters to be assessed by direct shear tests universe setting've been testing this end, the identification and classification, physical and mechanical properties of soil, direct shear tests on limestone soil with different percentages of 1 to 3 percent and then 1 to 4 percent clay and limestone the results show improved shear strength parameters modified by nano-clay composed of clay and limestone.