Since language is in the ever-changing process, taboo may vary depending on different age, region, occupation, speaker, context even in the same country and same race as well as different country and different race and resulting language variation may appear differently. Language variation according to taboo is very flexible and changed a lot in the language expression and appears differently depending on regions, folk differences, social background and passage of time. As everyone knows, every age has its unique social background and living contents and hence, when selecting the alternate language according to taboo, the exact expression suitable for the situation and context can be used only when fully considering if appropriate for the history and social customs of specific times. By considering both regional differences and synchronic, diachronic aspects about language variation according to taboo in Chinese and Korean and analyzing language extrinsic factors as well as the language format, this paper will examine language variation situation according to taboo and its operating principle. Research on this area can help to provide new insight for understanding changes in natural languages and improve felicitous language proficiency.