In the current scenario, the disposal problem of industrial by-products has become an environmental issue due to the pollution caused. This paper gives a review on replacements in concrete made out of various industrial by products like silica fume and steel slag in concrete. The main objective of my study is to in vestigate the feasibility of using steel slag as filler material and silica fume as admixture in concrete and to determine the optimum value of steel slag replacement in concrete. According to the earlier studies done by the researchers, the optimum value of replacement of steel slag and silica fume are in between20-70% and 10-40%. So through my study .I was decided to determine combined replacement of filler and admixture in concrete by steel slag and silica fume in  ( 40,50,60,70 )  and  ( 10, 15, 20,25 )  . This paper presents a detailed experimental study on Compressive strength, split tensile strength, flexural strength at age of 7and 28days and durability study on acid attack was also determined. The present study investigates the potential use and optimum usage of steel slag and silica fume in the production of concrete.