A side-chain liquid crystalline polymer based on p-methoxyphenyl-p‘-acryloyloxy benzoate was synthesized for utilization in a polymer dispersed liquid crystal. Phase diagram of the blends of side-chain liquid crystalline polymer and low molecular mass liquid crystal (K21) was established by means of light scattering and differential scanning calorimetry. A theoretical phase diagram was established by self-consistently solving the combined free energy densities of Flory−Huggins, Maier−Saupe, and phase field theory of solidification. The theoretical phase diagram was established to compare with the observed phase diagram of the binary mesogenic mixtures, showing the isotropic, isotropic + nematic (L1 + N2), nematic + nematic (N1 + N2), and crystal + nematic (Cr1 + N2) coexistence regions. The morphologies of these coexistence regions were further confirmed by polarized optical microscopy.