The N (p-n-octyloxy benzylidene) p-n-alkoxy anilines (8O.Om) compounds were synthesized, and the mesomorphic properties were characterized by using thermal microscopy (TM) and differential scanning calorimetry (DSC) for m - 3 to 7. The nematic (N), smectic-C (S(C)), and smectic-G (S(G)) phases are the more commonly observed in these compounds. The smectic-A (S(A)) and smectic-B (S(B)) phases are observed only in the 8O.O5 compound. The influence of oxygen on phase behavior of the 8O.Om compounds is compared with the data available on nO.m compounds.