Work on neutrino's mass has been going on in Japan and several other countries since the early work of V. Lubimov in USSR inl980 and that of a work with W. Kundig at Zurich University inl986. At the present time, there are several laboratories concerned with the research aspects of such particles. It among the advances of all sorts of neutrinos, two main cruxes should be considered for this subject. One is that the similarity between the photon and the neutrino, the other is that the very interesting superluminal theory for neutrinos.