The use of silica fume had major impact on industries, ability to routinely and commercially produce silica fume modified concrete of flow able in nature but yet remain cohesive, which in turn produces high early and later age strength including resistant to aggressive environments. This study is an experimental on the nature of silica fume and its influences on the properties of fresh concrete. The partially replacement of cement by silica fume the strength parameters of concrete have been studied. First the strength parameters of concrete without any partial replacement were studied then strength parameters by partial replacement with silica fume have been studied by placing cube on compression testing machine (CTM). Silica fume were used to replace 0% to 15% of cement, by weight at increment of 5% for cube. The results showed that partial replacement of cement with silica fume had significant effect on the compressive strength of cube. The strength of concrete increases rapidly as we increase the silica fume content and the optimum value of compressive strength is obtained at 12% replacement.
