The nano materials improve the mechanical properties of a cement concrete is a remarkable achievement in the field of nano composites. Matrix cement has a relatively loosely bonded structure which can be filled with Nano alumina which significantly improves the mechanical properties of cement. The present study discusses the development, manufacture and properties of the concrete made by nano materials. In the present study, the sulphate resistance of concrete is improved by the addition of Nano Alumina by partial replacement of cement. The study is carried out by partial replacement of cement by colloidal nano alumina- Al2O3 (CNA) particles with varying percentage (0%, 1%, 2%, 3%, 4%, and 5%) in the M55 grade of concrete. The study also evaluates an optimum dose of nano alumina at which maximum compressive strength of concrete is achieved with minimal sulphate attack observed in form of mass reduction in the concrete. It is observed that by an addition of 2.3% of CNA, the maximum sulphate resistance of concrete is achieved after 28 days. It was also observed that by an addition of 2% to 2.5% of Nano Alumina the compressive strength of concrete increases with a decrease in trend observed at 3% addition of Nano Alumina. © 2022