The purpose of this essay is to provide an analysis of the images of Duke Yin of Lu in the Three Commentaries on the ”Chunqiu” (Spring and Autumn Annals), so as to answer the question which has been central to the studies of classics and history: why the chronology of the ”Chunqiu” begins with Duke Yin of Lu? The ”Chunqiu” is so sparing in words that the ”Three Commentaries” has been essential to understanding the text. As a result, to clarify the point of views and ways of interpretation of the ”Three Commentaries” is prerequisite to answering the question at stake.The paper first indicates the pivotal importance of the images of Duke Yin of Lu in the studies of the ”Chunqiu” with critical review of past research, as well as the lack of a comprehensive approach in the previous studies. The paper continues by comparing the variance in the narrative of Duke Yin among the three commentaries, focusing particularly on the hierarchy between Duke Yin and Duke Huan, the difference between regent and abdication, and the conformity of Duke Yin's involvement in state affairs to ritual. The paper argues that the Duke Yin of Lu is often appraised in both Gongyang and Guliang commentaries as an individual human being but in different manners. The Guliang commentary makes efforts to depict Duke Yin's dilemma between filial piety and political sovereignty, and attributes his murder to his failure to fulfill the ritual expectations and controversies in behavior. In the Gongyang commentary, however, there is a more complicated kind of image, which stresses more on his efforts to balance the dilemma than the depreciation of his having no sense of priority as in the Guliang commentary. In the Zuo's commentary, Duke Yin, aside from being evaluated as an individual, is treated as a symbol of the state of Lu due to the Zuo's commentary's emphasis on the inter-states affairs of the ”Chunqiu” era. The Duke Yin of Lu in the Zuo's commentary is treated as a leader who fails to implement his agenda in the difficult situation from inside and outside the state. Such an interpretation reveals the state's frustration caused by the rise of the great power in early ”Chunqiu” era. And all these differences demonstrate how decisive genre could be in shaping characters and in the meanings of the narrative.