PREPARATION AND ASYMMETRIC ORIENTATION OF DIPOLAR DENDRONS IN AN ASSENBLED STRUCTURE SHIYOSHI YOKOYAMA and SHINRO MASHIKO CONCLUSIONS We made progress toward our goal of preparing novel dipolar dendritic materials based on electron donor/acceptor chromophoric branching. This Progress Was a result of: i) the stepwise synthesis of dendritic structures modified with azobenzene branching and alkyl chain exteriors; ii) the preparation of assembled structures by using the LB film transfer technique; and iii.).the characterization of asymmetrically arranged dendrons by using a sensitive surface proving technique for SHG measurement. We demonstrated the versatile application of present dendritic structures as second order nonlinar optical material. The experimental results indicated that the Introduction of a rod-shaped azobenzene derivative as the branching is an ingenious way of making the dendritic structure uniaxia1, and there is particular merit in this structure in generating SHG. The behavior of alkyl chains at the exterior of dendrons is also unique in the formation of assembled structures. our achievement in the present study is a combination of controlled material synthesis, the fabrication technique for molecular assemblies, and a sensitivity proving technique. We believe that such a technological combination would be especially useful in fabricating more complex supermolecular systems for future applications.