The German functional translation theory is proposed in the 1970s and 1980s. The functional sort of translation criticism is included from Katharina Reiss, Skopos theorie from Hans J. Vermeer, Justa Holz-Manttari's theory of translational action and Function plus Loyalty Principle from Christiane Nord. Vermeer's Skopos theorie is the key element of functional translation theory. It emphasizes interaction and pragmatic features of tranlation. He thinks the form of target language is firstly decided by function what is the purpose in the target language context.

We can distinguish between three possible kinds of purpose in the field of translation: the general purpose aimed at by the translator in the translational process, the communicative purpose aimed at by the target text in the target situation and the purpose aimed at by a particular translation strategy or procedure. Neverless, the term Skopos usually refers to the purpose of the translator. (Nord, 2001: 27-28) which is choosed by the originator of the translational action. 

2.1 Three Rules of Skopos Theory

We will take different strategy and methods if we have different translation purposes.That explains what is Skopos theorie. When translating, the translator should follow three general principle—Skopos rule, coherence rule and fidelity rule. 

Vermeer explains the Skopos rule in the following way: Each text is produced for a given purpose and should serve this purpose. The Skopos rule thus reads as follows: translate/interpret/speak/write in a way that enables your text/translation to function in the situation in which it is used and with the people who want to use it and precisely in the way they want it to function. (Nord, 2001: 29) 

Intratextual coherence specified that a translation can be read and accepted by readers, achieve coherence both the intertextual and the communicative context of translator receivers. That means translated text should be comprehended by target-text receivers with their own communicative situation and both cultures. 文献综述

At the same time, we have to know that since the target text is proposed according to the consitution offered in the original text, it is expected to support some kind of the relationship with the original text. This relationship is what Vermeer called “intertextual coherence” or “fidelity”. As in the case of the Skopos rule, the important point is that intertextural coherence should exist between source and target text, while the form it takes depends both on the translator's interpretation of the source text and on the translation Skopos(Nord, 2001:31). Among the three rules, fidelity should obey coherence, and both rules obey the Skopos rule. Nord proposed two translation ways: documentary translation and instrumental translation. The function of former is the document of original-culture communicative interaction for target-culture readership. It has a metatextual function and has four translation forms like interlineal translation, literal translation, philological translation and the exoticizing translation. The function of latter one is as instrument for target-culture communicative interaction modelled according to source-culture communicative interaction. Its target text includes refereatial/expressive/appellative/ phatic function and/ subfunction. Three forms of translation are equifunctional translation, heterofunctional translation and homologous translation. Though Skopos theory is related to documentary translation, it is a reader-centered or we can say target-culture-oriented theory basically. Under the circumstances, Skopos theory is espeacially suited for translating appellative and informative text.