Abstract: Due to the confusion use of two Chinese terms on mean tone temperament and equal temperament, Wohltemperirte (Well-temperament) of Das Wohltemperirte Clavier by J.S.Bach, which means temperament and its correct Chinese translation should be corresponding to pingjunlv (平均律) and no zhongyongquanyinlv (中庸全音律),is mistaken as equal temperament,while equal temperament is corresponding to dengchenglv (等程律). With the extensive development of international academic exchange, these common words in acoustics and music should be revised as soon as possible.

Key words: mean tone temperament, equal temperament, acoustics, musicology