Katsuhiko Ariga has been working on supramolecular chemistry especially related with self-assembly processes, ultrathin films and molecular recognitions. Accomplishments in his researches contribute significantly developments of biomemetic systems as well as physicochemical understanding on interfacial phenomena. Especially, pioneer researches of layer-layer supramolecular assembly have been highly evaluated, and he is also recognized as an authority of supramolecular recognition at the interfaces. Total citation of entire researches exceeded 7000 times. Now, his research team is working on frontier researches for supramolecular materials through entire bottom-up process.