Introduction: The quality of Zinc Oxide Eugenol-Ethoxy Benzoic Acid (ZOE-EBA) dental cement could be improved by the addition of Aluminum Oxide (Al2 O3 ). It was caused by the characteristic of alumina which are easy on fabrication process, resistant on corrosion, endurance usage, bioinert, and biocompatible. The purpose of this study was to determine the effect of the addition of Al2 O3 in ZOE-EBA cement. Methods: Nanoparticle of ZnO (zinc oxide), Al2 O3 , MgO (magnesium oxide),eugenol liquid and EBA (Ethoxy Benzoic Acid) fluid. The variations of Al2 O3 were 24%, 26%, 28%, 30%. First is the sintering on 1000°C and tested by XRD. Sintered powder was mixed with liquid, with a ratio of powder: liquid 7:1. The mechanical characteristic are compressive strength and hardness. Results: XRD test is showed that ZnO has dominant phase on the sample and there was new phase on cement powder such as Zinc-Aluminium oxide (ZnAl2 O4 ). The best result was shown on the addition of 26% of Al2 O3 composition in the 3 type test because the sample had ZnAl2 O4 phase volume fewer than 28% and 30% of Al2 O3 . This result was supported by the compressive strength and hardness which showed the optimum value at concentrations of 26%, which were 64.49 MPa and hardness of 69.33 VHN. Conclusion: Based on the result, it was found that Al2 O3 variation gives the best results in the teeth ZOE-EBA cement was 26%.