This paper intended to do a descriptive study of the ethics in the interpreting activities for the political and diplomatic fields in China and Korea. The description of on-site actual ethics is based on quantitative and qualitative analysis of consecutive interpreting data from 10 political and diplomatic occasions from 2003 to 2013. The ethics of source-target language relations are described through inter-textual comparison between source texts (ST) and target texts (TT). The description of the ethics in on-site interpreting yields findings in the following aspects: Through inter-textual analysis of ST-TT parallel corpus, three categories of shifts are discovered, including Type A "Addition", Type R "Reduction", Type C "Correction". The analysis showed that the three categories of shifts were representing the core meaning of the source text. Simply put, in the interpreting activities, the interpreter used the strategies of "Addition", "Reduction" and "Correction" to provide better interpretation services and deliver the core meaning of the speech very well. Not only "Equal", but also these three categories of shifts are also ethical behaviors. The interpreters used them in order to achieve the purpose of the inter-culture communication.