Photoisomerization in monolayers of a azobenzene dendrimer, was investigated for the first time by means of the absorption spectrum and Maxwell displacement current ( MDC) technique. Dendrimers are well-defined macromolecules exhibiting a treelike structure, first derived by the cascade molecule approach. According to the absorption spectrum, trans-to-cis conversion ratio was estimated to the generation of azobenzene dendrimer. Charge with trans-cis isomerization was also measured by means of MDC technique.