Molecular coatings of thiol-terminated organic compounds such as thiol-terminated polystyrenes and alkanethiols were formed on nickel surfaces by means of interaction between nickel and thiol groups in order to investigate air oxidation resistance properties of the surface by the coatings. CV and LSV measurements indicate the organic layer prevents the nickel surface from both electrical oxidation and oxidation in air. Thiol-terminated polystyrene provides higher heat resistance than alkanethiols while maintaining electrical conductivity.