Covalent bonds with the ability to reach an equilibrium state between cleavage and formation under certain conditions have been studied, and systematic method for controlling the structures of compounds and polymers based on these reversible and exchangeable covalent bonds has been spotlighted as dynamic covalent chemistry. In the present review, various types of “reactive” soft materials based on dynamic covalent chemistry are described. Exchange reactions of alkoxyamines, olefins, disulfides, and diarylbibenzofuranones derivatives were employed. The reactive soft materials based on these exchangeable units were prepared and their reorganizability was systematically shown.