Dynamic molecular assembly using reversible covalent bond is focused on supramolecular chemistry, recently. We designed a dynamic molecular assemblies using esterification between phenylboronic acids and triol compounds. Any molecular assembly was immediately formed by only mixing in solvents between the bifunctional phenylboronic acid derivatives and the bistriol compounds. As a result of characterizing the structure of molecular assemblies, formation of cyclic complexes and acyclic complex oligomers are observed. The change of the structure of molecular assemblies was not only depending on enthalpic effect by esterification, but also on entropic effect like flexibility and a degree of freedom in the molecular structure. It is triggered by varying concentration and temperature. In this presentation, we introduce the design of macrocyclic molecules and a gelator.