Soil stabilization is a process which permanently changes the physical and chemical properties of soil. Soil stabilization is used to improve the bearing capacity of poor sub grade or sub-base soil to make it suitable to support structures like pavements, railways, foundations etc. Addition of nano particles to natural soil materials are often used to affect soil atomic structure thereby changing its permeability, strength and resistance properties. The addition of Cement (OPC) and terrasil is known to improve the strength of soils. This project primarily deals with the investigation of the strength characteristics of block cotton soil when mixed with a range of proportions of additives such as terrasil, fly ash and cement using CBR and UCC tests. The natural soil was tested according to Indian standards. The soil is classified as CH. Addition of cement and terrasil were based on the guidelines given by the ZYDEX Company. The test results show that the CBR and UCC values are similar for the proportions Cement (OPC) (3%) + terrasil (0.1%) and cement (OPC) (2%) + fly ash (5%) + terrasil (0.1%).