Metaphor has been under study for a long time. However, the traditional study of metaphor has been confined to the study of metaphor as a common rhetorical means. Since the 1970s,the study of metaphor has showed a tendency to study form varied angles, in varied levels and on varied subjects. Although there are different opinions on the differentiation between metaphor and non-metaphor in languages and the objective and ways of study, an agreement on the cognitive function of metaphor has been reached among most researchers. It is believed that metaphor in not only one kind of rhetorical means but also a way for human being to understand the world.“Language is metaphorical in nature because the basic mode of mens thinking is metaphorical"(Lakoff, 1992).As a kind of cognitive phenomenon, metaphor can be used to analyze and explain the various phenomena of language so as to help people to gain a comprehensive understanding of the intrinsic structure of language. The purpose of this thesis is to exploit the cognitive mechanism of metaphor to probe into the nature of translation. Translation is usually regarded as a form conversion between two different language systems but indeed it is an active cognitive activity of the translators. In translation the metaphorical mapping and the incompatibility take place between two languages. As a way of thinking, metaphor can also be used to analyze the conceptualization of the objects and events in different cultures. Here the western metaphorical cognition theories (Conceptual Metaphor Theory and Blening Theory) is introduced to make preliminary exploration of the thinking process of translation in order to help us to get a further understanding of the nature of translation and the essence of different translation theories. The translation process can simply be referred as a process of understanding the source language in terms of the target language, which is in essence a cognitive process between two domains (e.g., the source language domain, the target language domain). As conceptual metaphor theory (CMT) focuses on characterizing such cross-domain mappings that define an open-ended class of potential correspondences across inference patterns, the way of thinking in translation is explored in the thesis with CMT, which contributes to discover the comprehension process of translation. However, as the phenomena accounted for by CMT consist of stable knowledge structures represented in long-term memory ,it fails to provide a detailed description of the on-line process in which the concepts in source language domain are mapped to that of the source conceptual network. Another defect of only applying CMT is that it defines metaphor as a strictly directional phenomenon and a one-way mapping between source language and target language. The advantage of the Blending Theory (BT) over only applying CMT is that BT takes the translation process as a blending process that initiates entrenched metaphors in both language networks and yields short-lived and novel conceptualizations to complement them. Moreover, BT seeks to model the dynamic evolution of speakers on-line representations. Differences between conceptual metaphor theory and blending theory, such as the distinct nature of directionality in the two frameworks, may lead us to treat them as competing theories. But here we would rather propose that the two frameworks be largely complementary in revealing the nature of translation process for they deal with different aspects of metaphoric conceptualization. The conventional conceptual pairings and the one-way mapping studied within CMT are inputs to and constraints on the kinds of dynamic conceptual networks posited within BT . If we ascertain that the findings of CMT and BT are consistent, the potential rewards are significant since it allows us to unify two streams of research into a more general and comprehensive treatment of linguistic and conceptual phenomena, which will be of great help to the understanding of the translation process. Since these two streams of research deal with different aspects of the same data , it makes easier for us to generalize across a broad range of metaphoric expressions as well as focus on the particulars of individual examples. Besides a comparatively specific analysis of the function of the two theories in elucidating the nature of translation, this thesis also discusses some other factors that also affect the cognition process of translation like context and culture, uncovers the reason for the breakdowns that occur in translation from the perspective of cognition. In addition, the cognition theory is applied to a through understanding of the translation of poetry. It is found that the cognitive mechanism of metaphor plays an important role in explicating the cognition process in translation and grasping the nature of translation. It is therefore suggested that further exploration and description of the mechanism of metaphor and the characters of translation is needed for improving the research on the theories and the practice of translation.