We synthesized the p-nonyloxyazobenzene derivatives with functional structures and carried out this experiments to observe photoisomerization irradiated by alternate lights. We found that it was reversibly induced to cis-trans photoisomerization in several solvents. Spreading solutions for the LB films were prepared in chloroform($1.2{ imes}10^{-2}$ mmol). As a result, it is found that the absorption spectra of the LB monolayer films was induced to photoisomerization by alternative irradiation lights, temperatures and pH(HCL and $NH_3$), respectively.