Two unsaturated liquid crystalline compounds based on diamine:N,N′-[oxybis(4,1-phenylene)]bis{4-[2-(allyloxy)ethoxy]benzamide} and N,N′-[methylenebis(4,1-phenylene)]bis{4-[2-(allyloxy)ethoxy]benzamide}were synthesized from 4,4′-diaminodiphenylether(DDE) and 4,4’-diaminodiphenylmethane(DDM),allyl-2-hydroxyethyl ether,4-hydroxy ethyl benzoate by the procedure of acylchlorination and esterification.The structures and liquid crystalline behaviours were investigated by DSC,FTIR,1H NMR,POM and XRD.The results showed that these compounds were all smectic phase and had a higher liquid temperature range,in which the melting points of two compounds were 240 and 220℃,respectively,and their clear points were all higher than 300℃.