Jen is the most important idea in Confucius' thought. In the Analects Confucius discussed and interpreted jen repeatedly. Henceforth, a good number of Confucians in history also wrote down their understandings and interpretations of jen. Among them, Sung-Ming Neo-Confucians were quite distinctive in stressing the importance of returning to Confucius and Mencius as well as of moral practice. In this paper, I first macroscopically outline the genealogy and two approaches of the Sung Neo-Confucian interpretations of jen. Then, I microscopically analyze with the example of ”Kuan-kuo ssu chih-jen i” of the Analects the two different interpretations of Chu His and the Hu-Hsiang School. Lastly, I emphasize that ”a subjective shift” is the main characteristic of Sung Neo-Confucians' interpretations of jen.