In this work, Mg-doped Al2O3 supports were used for the preparation of Ni catalysts, which were then tested in dry reforming of methane reaction (DRM) for syngas production. The influence of MgO content (0-70 wt%) on the basicity of the catalysts as well as on the formation of a NiO-MgO solid solution was investigated and linked to the catalytic performance of the catalysts. The catalyst containing high amount of Mg (Ni/70MgAl) showed the best performance with negligible deactivation rate over 50 h of time on stream (TOS). The presence of strong basic sites in this catalyst was important to adsorb carbon dioxide (CO2), to gasify the coke deposit and to increase the syngas production. Also, the presence of a NiO-MgO solid solution led to strong metal-support interaction, which limited the sintering of nickel particles. The quantification of the water formed during the reaction showed that its formation was crucial for the elimination of the coke deposits as well as to increase the syngas production.