The adhesive secretion of the mussels became of interest in recent years because of its strong adhesion to practically all known surfaces, such as rocks, metals, glass, and plastics immersed in seawater. The strong adhesives secreted by marine mollusks, such as the barnacles and mussels, are simple proteins. These proteins are designated marine adhesive proteins in mytilid bivalves. Their adhesive properties have been investigated from basic scientific interests, as well as their use as adhesives for medical and dental purposes, which suggest many challenging problems. The present paper describes the recent results concerning the adhesion mechanism of synthetic marine and their related adhesive polypeptides from the following viewpoint of polypeptide and protein chemistry: i) their molecular structure and insolubilization, ii) the kinetics of the enzyme reaction to convert the Tyr residue into Dopa, and iii) the relationship between the oxidation kinetics and their conformation.