Mercaptopyridine and its analogues cause a tautomerization reaction between their thiol and thione isomers. The equilibrium state would be changed by the surrounding environment such as polarity. In this study, we have designed and synthesized a vinyl monomer having a 2-mercaptopyridyl moiety, and prepared a photoadhesive material including the monomer, 2-hydroxyethyl methacylate, and a photoradical initiator. Photoadhesion between various kinds of adherents was realized using this material with 6.0 J cm -2 of UV irradiation at a wavelength of 365 nm, recording up to 8.8 MPa of shear strength. The effects and chemical states of 2-mercaptopyridyl moieties were examined by control and/or XPS spectral measurements. Interestingly, the adhesive strength increased gradually, indicating an autoxidation reaction between two 2-mercaptopyridyl moieties to form a disulfide bond and cross-linked polymer networks.