Culture-loaded concepts and words pose as the greatest difficulty in the translation of classic texts. Translators need to take into account all the following: preciseness, smoothness, faithfulness and unified diction through the whole passage. Different cultural traditions between the East and West nurture different historical and cultural soil for the development of thinking styles, which leaves specific traces on the formation of words and expressions of certain concepts. Those concepts, rich with peculiar connotations, even from the classic texts of ancient times, cannot be translated without deep pondering of their associations. Otherwise, one might easily fall into the trap of their superficial meanings and instill meanings and associations totally alien to the other culture into the target language. Furthermore, while some concepts have no exact correspondence, some others might not exist at all in another culture. In this case, proper choice is called for in translation. For example, the traditional Chinese concept of “yin-yang” is totally foreign to the western culture. Therefore, translation versions such as “positive and negative” or “plus and minus” fail to reproduce the connotation of the source concept, which renders most translators no other choice but the use of “yin-yang”, a transliteration. For another instance, “original sin” in Christian tradition of the West is translated into “原罪 (yuan zui)” in modern Chinese. However, “sin” and “罪 (zui)” are not corresponding to each other conceptually, and thus cannot be treated as equivalent in the translation of classic texts. This paper explores the translation of “德 (De)” in Sources of Chinese Tradition (ed. by de Bary and Bloom, 1999), which is used by most American and British universities as a textbook to teach Chinese traditional culture and thinking. Difficulties in the translation of Chinese cultural notions and concepts will be discussed.