Almost of dental materials do not appear a good seal from microorgansims entre. Thus, a microscopic space is may be exist at the interface between the packing material and the walls of the root end cavity, that is allowing microorganisms and their products to penetrate, and also to a perfect sealing capacity with biocompatibility, root fillers should ideally contain an antimicrobial efficacy. Therefore, this is study targeted to estimate the antimicrobial activity of zinc oxide polycarboxylate cement (ZPCC) and its composites with aluminum oxide nanoparticles, Al2O3-ZPCC, & Green-Al2O3-ZPCC. The antimicrobial properties of ZPCC and its composites spread technology were tested against for E. coli, S. aureus, as well as Candida albicans. Based on the antimicrobial activity results, the addition of aluminium oxide nanoparticles to ZPCC improved its antimicrobial activity.