Three large mesoporous alumina powders were prepared by microemulsion (ME) method with different microemulsion structures and compositions (various surfactants and oil phases) and employed as catalyst carrier for preparation of mesoporous nanocrystalline Ni/Al2O3 catalysts. The prepared catalysts were used in dry reforming reaction for production of synthesis gas. The samples were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller surface area analysis (BET), temperature programmed reduction (TPR) and scanning electron microscopy (SEM) techniques. The results showed that the prepared gamma-Al2O3 with different microemulsion compositions possessed mesoporous structure with high surface area from 239.7 to 277.7 m(2) g(-1). In addition, the prepared 10wt.% Ni/gamma-Al2O3 catalysts exhibited high activity and stability in dry reforming reaction. The results also revealed that the microemulsion composition have a significant effect on the textural properties and affected the catalytic performance. Copyright (C) 2016, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.