A novel homologous series: RO-C6H4CHCHCOOC6H4CHN-C6H3 (CH3)(2) of ortho-meta Schiff's bases has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on mesomorphic properties and to provide a source of novel liquid crystalline (LC) materials. The series consists of 13 homologues (C-1 to C-8, C-10, C-12, C-14, C-16 & C-18). C-1 and C-3 homologues are nonmesomorphic, C-2 and C(4)monotropicnematic, C-6 and C(7)monotropicsmectic in addition to enantiotropicnematic, C-5 is only enantiotropicnematic, C-8, C-10, C-12 are enantiotropically smectogenic plus nematogenic and C-14, C-16, C-18 homologues are enantiotropically smectic only. Textures and transition temperatures were determined using an optical polarizing microscope equipped with a heating stage. Analytical and spectral data confirm the molecular structures. Average smectic and nematic thermal stabilities are 100.16 degrees C and 110.83 degrees C, respectively. Mesomorphic properties of present novel series are compared with structurally similar homologous series.