Abstract: By comparing Drude classical electron theory of metal with London equation of superconductor those are taught in electromagnetism, author indicates that by use of the same method and different phenomenological model for different objects completely different conclusions have been obtained; from macroscopic domain to microscopic domain phenomenon to essence the developing of physics generally passes through phenomenological theory; how properly to introduce the knowledge of the frontier and progress in science to students is a task which is the focus of people attention, however London equation is the best template.

Key words: classical electron theory of metal, superconductor, London equation, phenomenological theory