Expansive soils cover more than twenty-two percent of geographical area of India. These soils shrink and swell, respectively, with the decrease and the increase in water content of soil. In this study, experimental tests were conducted on an expansive soil to study the effect of mixing of potassium chloride on various soil properties. Liquid limit, swelling potential and plasticity index were found to be reduced significantly with mixing of potassium chloride. Initially, for potassium chloride of 6-8%, plastic limit has also been reduced but latter, it increased with the increase in quantity of potassium chloride. Mixing of potassium chloride increases and decreases, the maximum dry density and optimum moisture content, respectively. The mixing of potassium chloride increases the unconfined compressive strength and shrinkage limit of soil. Optimum amount of potassium chloride is found to be approximately 8-9% of dry soil weight. Potassium chloride altered the properties of expansive soil significantly, and most of the modifications are found to be favourable from civil engineers’ point of view. Results of the present study are compared with previous study results too.