Nano-sized Ni catalysts were prepared by using MgO-Al 2 O 3 mixed oxides from hydrotalcite-like structure as a support. The property of support was controlled with various Mg/Al mixed ratio to enhance coke resistance in combined H 2 O and CO 2 reforming of CH 4 (CSCRM) to produce synthesis gas (H 2 /CO=2) for gas to liquid (GTL). 12% Ni/MgO-Al 2 O 3 catalyst with Mg/Al of 0.5 shows the highest activity in CSCRM due to high coke resistance, resulting from nano-sized Ni particles strongly interacting with the support.