A novel photo-driven liquid crystal (LC) cell was fabricated by sandwiching nematic LC molecules between two quartz plates whose surface was modified with 4-hexyloxy-4'-undecanyloxyazobenzene (6Az11)-grafted ladderlike copoly(methylhydrosilsesquioxane) (PMHSQ). Reversible changes of the alignment between homeotropic and planar modes were achieved. The transmittance through the cell and crossed polarizers could be controlled by the irradiation intensity of 365 nm UV light. A high contrast ratio over 100:1 was obtained.