Abstract: In India expansive soils are called as Black Cotton Soil. These soils pass high strength in summer and decrease rapidly in winter. behavior of these soils is different than other soils due to behavior of its structure conditions. When BCS is appears very hard with high bearing capacity to sustain imposed loads from buildings, but when wet it absorbs large volumes of water, swells rapidly, soften and loose their high bearing strength and loose their high bearing strength. The effect of saline water i.e. Salt water which is generally found at the seas shores has an adverse impact on the geotechnical properties of soil. There have been many studies which show that the presence of salts on the soil is observed in many ways. The Atterberg limits, compressive index and swelling index decrease and consolidation coefficient and shear strength parameters increase as pore water salinity increases. There is no dispersion in soil in contact with saline water as showed in the dispersion tests showed. The use of NaCl is done here in our tests and then samples of various percentage is done. hey for the proper understanding of the behavior of soil hey when reacted with Saline water hey it must be mixed in proper concentration and the effect on the geotechnical properties of soil must be studied. Common salt is white in colour and is present in the form of crystals. It lowers the vapor pressure of water. It also reduces or prevents frost by lowering the freezing point of water. Common salt is easily available in market so the cost of transportation will be reduced. In this study we will find out the effect of Salt on the geotechnical properties of soil.KEYWORDS: Saline water, geotechnical properties, salts