Abstract: The paper discusses the characteristics of copper tetrakis-(2,4-di-methyl phe-noxy)phthalocyanine(CuPc)and nickel tetrakis-(2,4-di-methyl phenoxy) phthalocyanine(NiPc)on the gas-liquid interface. The corresponding Langmuir-Blodgett(LB) films were prepared.It was confirmed that phthalocyanine molecules would lie flat on the substrates in dimers by UV-Vis and polarized UV-Vis spectral method. The LB films were used to align nematic liquid crystal E_7.Under a polarized microscope and the conoscopic system,the align-ment of the liquid crystal was observed on the LB films.The electro-optieal measurement was carried out.The mechanism of alignment was also discussed.