Abstract: The semantic ranges of a technical term are not equal in different languages due to the experiential factors like cultural cognition,linguistic characteristics etc. So the translation of a technical term is a complex dynamic matching procedure between languages. Accurate translation of new technical terms is an important academic issue scientists and terminologists are concerned about. Taking semantic theory as an analytical framework and through a case study on the C-E and E-C translation of "Shui Zi Yuan Guan Li", we found that the semantic ranges of technical terms in a particular semantic field will experience dynamic changes along with the refinement of their definitions due to the progress of related researches. The translation of new technical terms should fully consider the previous translation and use of other related technical terms in the same semantic field, and make a balance between the preciseness of translation and the easiness of interpretation. This explains why the translation of "Shui Zi Yuan Guan Li" and related terms is very complex, and why it deserves more attention.

Key words: semantic field theory, “Shui Zi Yuan Guan Li”(water resources management), technical terms, translation of science and technology, cognitive reference point