Fly ash is very effectively used in various civil engineering projects. Fly ash is a by-product of coal burning thermal power plants plant. The quantity of coal ash produced depends upon the quality of coal and the method of burning of the coal. In India less than 20% of ash is used in the manufacture of brick, cement, concrete and other product. Sand particles are much coarser than the fly ash. Here we are using different proportion as 100%S, 80%S+20%FA, 60%S+40%FA, 40%S+60%FA, 20%S+80%FA, 100% FA. Different test like Grain size analysis Specific gravity, Standard proctor test, Permeability test, direct shear test, California Bearing Ratio test were done on different proportions. MDD increases while dry density decreases as Sand increases. Permeability decreases as fly ash content increases. CBR value decreases for both soaked and unsoaked condition as fly ash content increases.