【正文】 ans of other signs in the same language), (2) interlingual translation or translation proper (an interpretation of verbal signs by means of some other language), (3) intersemiotic translation or transmutation (an interpretation of verbal signs by means of nonverbal sign system). He regards these three types of translation as the fundamental means of understanding linguistic signs. In his opinion, translation means the substitution of information in the original for that in another language. It is obvious that Jacobson’s theory is based on his semiotic approach to translation according to which translator must first recode the SL message and then he or she has to transmit it into the equivalent message in TL.Catford is considered as another key theorist in studying translation equivalence. He has a more linguisticbased approach to translation than his contemporaries and his theoretical basis is mainly based on the linguistic work of Halliday. He introduces the distinction between formal correspondence and textual equivalence in his book A Linguistic Theory of Translation. In his view, translation can be interpreted as the replacement of textual material in one language by the equivalent textual material in another language. (Catford: 1965)A textual equivalence is, according to his explanation, that any TL text or portions of text, which is observed on a particular occasion, should be the equivalent to a given SL text, or portions of the text. A formal correspondence is, on the other hand, “any category (unit, class, structure, element of structure, etc.) which can be said to occupy as nearly as possible, the ‘same’ place in ‘economy’ of TL as the given SL category occupies in the SL”. (Shen Yuping, 1999:290). His contribution to the science of translation is his notion of ‘textual equivalence’ and his disagreement with ‘formal equivalence’. He holds that there is no meaning equivalence but only denotative equivalence. SL textual and TL textual units therefore have, linguistically speaking, only rarely the same meaning, yet in parable intelligent situational contexts. They can serve the same units and TL textual units are equivalent if they can be exchanged in a given situation.Another heavyweight in developing the equivalence theory is Wilss. He defines translation as “a transfer process which aims at the transformation of a written SL text into an optimally equivalent TL text, which requires the syntactic, and the semantic and pragmatic understanding and analytical processing of the SL text”. (Wilss, 1982: 3) Obviously, his approach to translation is also based on semiotics and he thinks that equivalence should be realized in three aspects, that is, syntactic, semantic and pragmatic. His “optimally equivalent” is reasonable, but as to how to achieve this, he makes no answer.One of the most influential scholars of this school is Eugene A Nida, whose books are among the most popular published in China. Many translators today have been influenced by his work and theory. Translation, as Nida puts it, is “the replacement of a representation of a text in one language by a representation of an equivalent text in a second language.” (Meetham and Hudson, 1972:713) The key word in this sentence is ‘equivalent’. It prescribes that translation is not a random transformation from one language to another, but should be based on a criteria, that is, equivalent. In his book Toward a science of Translating (1964), Nida distinguishes two types of equivalence: formal equivalence and dynamic equivalence. He defines formal equivalence as follows: formal equivalence focuses attention on the message itself, in both form and content… One is concerned that the message in the receptor language should match as closely as possible the different elements in the source language. (Nida, 1964:159) so it is clear that the notion of ‘formal equivalent’ is sourcelanguageoriented and this kind of translation is to achieve as much as possible the form and content of the original message. He explains it further: a formal equivalence attempts to reproduce several formal elements: (1) grammatical units, (2) consistency in word usage, and (3) meanings in terms of the source context. The reproduction of grammatical units may consist in (a)translating nouns by nouns, verbs by verbs,etc. (b)keeping all phrases and sentences intact (. not splitting up and readjusting the units), and (c) preserving all formal indicators, . marks of punctuation, paragraph breaks, and poetic indentation.(Nida,1964:165)It seems that ‘formal equivalence’ is more like wordforword translation. That is why people take formal equivalence in translation as another name of wordforword translation. In this way, it is difficult for the target readers to prehend the real meaning of a source text. In the Theory and Practice of Translation, coauthored with Taber, Nida asserts “typical formal correspondence distorts the grammatical and stylistic patterns of receptor’s language and hen distorts the message, so as to cause the receptor to misunderstand or to labor unduly hard.” (Nida and Taber, 1969:201) Nida makes it clear that there is not always formal equivalence between two languages, and formal equivalence should be used wherever possible if the translation aims at achieving formal rather than dynamic equivalence.Nida’s Dynamic (functional) equivalence is based on what he calls ‘the principle of equivalent effect’, . the relation between the TL receivers and message should aim at being the same as that between the original receivers and SL message. That is, the translation should produce the same effect on the readers as the source language does.In his later study, Nida begins to use functional equivalence to replace dynamic equivalence. He explains the relationship between functional equivalence and dynamic equivalence in his book Toward a Science of Translation, in which he writes: “dynamic equivalence has been treated in terms of the ‘cl