One of the most promising uses for alumina nanoparticles (Al2O3 NPs) is in analytical chemistry, where their excellent physiochemical characteristics make them stand out from other metal oxides. Adequate dispersion and adequate interfacial contact between the reinforcer and the polymer matrix are required to use the Al2O3 NPs as an efficient nano-filler in the polymer nano composites (NCs). Al2O3 NPs have organic coupling agents grafted onto their hydrophilic surface for this purpose. Polymer/Al2O3 nanocrystals (NCs) have been the subject of much study over the last several decades, with researchers primarily interested in exploring the material's structure-property correlations as it evolves. This review provides a narrative explanation of the principles, methods, and effects of dispersing and modifying Al2O3 NP in polymer/Al2O3 NC