Chomin Nakae is a famous thinker in Meiji period. Among his thoughts, the diplomaticthought is an important component. By analyzing On Diplomacy(1882), A Discourseby Three Drunkards on Government(1887) and Chomin Nakae’s comment after theSino-Japanese War of1894-1895, this paper discusses the content and change of ChominNakae’s diplomatic view and explains the further cause of the change.Chomin Nakae’s diplomatic view has changed a lot from “moral diplomacy” toexclusivity and expansionism. What are the reasons that cause his contradictory diplomacy?When these reasons become clear gradually, then what is the enlightenment to us? These arethe issues that this paper is going to study.Our domestic study of Chomin Nakae mainly focuses on his thought of philosophy,politics, as well as how he was effected by Chinese culture. The study, which began in1980s,first started with his philosophical thought. With time passing by, other aspects were graduallydiscovered by people. To sum up, the number is increasing, the quality is improving but thecoverage of the study is not enough. However, for a thinker who played an important role inJapanese modern history, our domestic study does have its deficiencies.