The thermal behaviors of various benzoic acids and liquid crystal forming p- alcoxybenzylidene-p-aminobenzoic acids in poly(N,N-dimethylaminoethylmethacrylate) were investigated. It was found that these liquid crystal forming benzoic acids do not form salts with the dimethylehylamino groups of the host polymer, and formed nematic liquid crystal particles dispersed in the polymer. The melting point of the host polymer decreased from about 200-degrees-C to around 140-degrees-C by the addition of the acids. On heating the mixture the acids were gradually dissolved in the polymer, and totally homogeneous mixtures without liquid crystalline phase were formed.