A dynamic holographic technique based on two phase-modulated coherent optical beams mixing was applied for a photoconductor polyimide-liquid crystal structure investigation. Deep modulation of the output beams intensities confirmed high optical non-linearity of these structures. A spatial mismatch between the beams interference pattern and the recorded grating was observed indicating the liquid crystal molecules orientational anisotropy. The kinetics of holographic gratings recording and erasure demonstrated a complicate non-monotonous behavior which could be a result of the photoexcited electric charge drift and diffusion.