Gas phase N-methylation of aniline with methanol was carried out in a fixed bed flow reactor over the calcined Mg-II-Al-III layered double hydroxides (LDH) with various atomic ratios of Mg:Al from 3 to 10. Only a single product (N-methylaniline) was formed. The catalytic activity, selectivity, longevity, time on stream and reactivations are investigated based on the extent of mono-alkylated product formations. All calcined LDHs were more active than the physical mixtures of MgO-Al2O3. A higher surface area and lattice parameter of 4:1 mole ratio of calcined LDHs effectively produced a maximum conversion of 68% at 425 degrees C at a feed mixture mole ratio of 1:7 (aniline to methanol) when the flow rate was 5 ml/h over all other catalysis.