【正文】 some others may change or even disappear. As mentioned in the part of history of euphemism, euphemisms originated from taboos, the earliest of which are related to religion because of people’s fear of Gods. Gradually, the euphemisms about Gods bee decreasing with people’s increasing awareness of the natural phenomena.As for the particular case of change, we can take the word “trousers” as example. It was once a euphemism and was replaced by “indescribable, unspeakable or situpon”. But all of us are now talking about “trousers” so freely and directly whenever we want to.It can be asserted that there are fewer taboos nowadays than that of centuries ago, therefore, in some aspect the scope of euphemism is narrowing down. However, at the same time, there also appear some new euphemisms with the development of society.Euphemisms vary diachronicall。 Silver, 1983: 4). Later, the word euphuism came into being when author John Lyly employed it in a satirical work called Euphues (1578). By the early 1580s, the author George Blount used the term “euphemism” in English, defining it as “a good or favorable interpretation of a bad word.”After the Puritan revolution, the restrictions against overtly sexual language were not so strict than that in the seventeenth century. A large number of new and colorful terms for body parts and sexual practices could be heard on the stage and read in the new literature. But political language was still used with great caution.By the nineteenth century, middleand lowerclass influence had expanded, by whom the vocabulary and formation of euphemisms has been enriched. During the eighteenth and nineteenth centuries, British euphemism was developing abroad as well as at home, and euphemisms in Canada, Australia and America went after the patterns of formation of the English middle class.From the beginning American euphemisms reflected the desires for both piety and pleasantness and the tendency to genteelize was apparently especially popular among American women. Great changes did not take place until 1920s and the greatest changes appeared after World War Ⅰ and Ⅱand during the 1960s counterculture movement. In the 1980s, with the development of the society, money, disease, politics and war were the richest subjects of American euphemism. At the present time, euphemism is widely used in almost every field: economy, politics, physical, health, social occupations, crime and so on. Euphemisms are powerful linguistic devices, which are embedded so deeply in our language that few of us, even those who pride themselves on being plainspoken, ever get through a day without using them. (Rawson, 1981: 1) Features of Euphemism As a linguistic phenomenon as well as a kind of municative strategy, the features of euphemisms can be summed up as follows: UniversalityEuphemism, as a language phenomenon, can be found in all nations throughout the world, whether it is a highly civilized nation or a primitive society. Euphemisms are embedded so deeply in our language that few of us, even those who pride themselves on being plainspoken, ever get through a day without using them. (Rawson, 1981:1)No matter what the language is, there are numerous euphemisms in it. No matter who a person is, he uses euphemisms time and time again. Euphemism is so prevalent in our language that some people use euphemisms without awareness. They say that they are going to the bathroom when no bath is intended. The euphemism bathroom is so frequently used that it tops other euphemisms of this kind. Hence, no one can deny the universality of euphemisms. VaguenessEuphemism is also characterized by vagueness. Many euphemisms are formed by means of obscuring the real meanings of the expressions. Let us take a vague term as an example: go is a very mon word that is frequently used in many occasions. While as a euphemistic term, its vagueness can be employed to refer to urination or defecation. As the example in Liu Chunbao’s Dictionary, “Mama, I have to go now.” (Liu Chunbao, 2001:240)Here, this go is the euphemistic expression of urination or defecation. The word certain can also be highly euphemistic in terms of making the reality vague: a woman in a certain condition is pregnant。 Silver (1983), the subject of the earliest euphemism was undoubtedly religious. Since in ancient times, people could not explain some natural phenomena, they considered them as the result of Gods’ control. Gods, whether benign or malevolent, were treated with respect amounting to terror. Since the names of gods were considered identical with themselves, to speak a name was to bring forth the divinity whose power they had to confront. Therefore, gods were never referred to directly but by their attributes, symbols or titles. Perhaps the most mysterious of all the types of religious euphemism was that convoluted variety which referred to the gods by naming what they were not. (Neaman amp。 Silver, 1983). It has to be admitted that the appearance of euphemism cannot be separated from the phenomenon of language taboo from which it originates. As Ronald Wardhough claims, “Certain things are not said, not because they cannot be, but because ‘people do not talk about those things’。s own thoughts, feelings. By observing and analyzing the euphemisms in our data, we attempt to find out some rules from them and the cognitive motivation underlying them.The present thesis is posed of six parts. Following chapter one of introduction, chapter two reviews the development, history, formation, features and classifications of English euphemisms meanwhile we will also have a general review of the previous and present studies of euphemisms from the perspectives of rhetoric and fuzzy linguistics, pragmatics, semantics, sociolinguistics and psycholinguistics in this chapter. Chapter three sets up the theoretical framework for our study by discussing conceptual metaphor theory. Since the cognitive approach to metaphor is