Starting with the definition of taboo language,specifically addressed the "death" taboo language of Japanese ritual,this paper is based on specific analysis on part of the "death" taboo language to clarify the taboo language itself and its functions change with the times.It also further clarifies the importance attached to taboo language.Its existing form is gradually fading with times change and science development,but will exist for a long term.By researching and exploring the phenomenon of Japanese social and cultural phenomenon behind taboo language,it can help to grasp the Japanese national psychology,and promote the smooth ness of cross-cultural communication.