Liquid crystalline binary systems, consisting of poly(vinylalcohol) and an amphiphilic compound with hydrophobic nitroazobenzene and hydrophilic ethyleneimine units, were prepared, and their thermal and liquid crystalline properties were estimated. The amphiphilic compound exhibited a smectic A phase with a focal conic fan texture. The liquid crystalline binary systems showed a thermotropic smectic A mesophase. In the smectic A phase, a smectic layer structure with hydrophobic and hydrophilic sublayers was formed.