In the present short review, we briefly overview the history of ice polymorphism under high-pressure and the recent progress on impurity ices (clathrate ice, salty ice, doped ice, empty ice, etc.), including our contributions due form high-pressure Raman investigations to these research fields. In particular, the unique roles of impurities in ice, which are (1) acceleration of proton ordering at lower temperatures, (2) offering a clue to form new ice phases, and (3) phase transitions other than the original equilibrium stability region of pure H 2 O, ice are introduced. Then, as prospects, we address promising impacts on a new area of ice physics with the active use of impurities.